Free shipping for all orders of $99

Free Shipping For All Orders Above $99

Select category
  • Select category
  • Sailboat Equipment
    • Burgees & Flags
    • Instruments & Electronics
      • Electronics By Brand
    • Sailboat Canvas
      • Beam & Tramp Covers
      • Boom Tents & Bimini Covers
      • Bottom Covers
      • Bow Covers
      • Cockpit Covers
      • Envelope Covers
      • Fender Covers
      • Hatch Covers
      • Headsail Covers
      • Headstay Covers
      • Mast Bags & Covers
      • Mooring Covers
      • Plank Bags
      • Rudder Tiller Covers
      • Sail Bags & Covers
      • Sheet & Store Bags
      • Sock Covers
      • Spinnaker Bags
      • Spreader Bags & Covers
      • Tiller Covers
      • Travel Deck Covers
      • Travel/Mooring Covers
      • Wheel Covers
      • Winch Covers
      • Yard Covers
    • Sailboat Steering
      • Alloy Tillers
      • Aluminum Tillers
      • Carbon Fiber Tiller
      • Pintles & Gudgeons
      • Rudder Blades
      • Rudder Hardware
      • Telescopic Tillers
      • Tiller Accessories
    • Sailboat Trailers & Dollies
    • Sailing Accessories
    • Trapeze Equipment
    • Wind Indicators
  • Sailboat Hardware
    • Anchoring & Docking
      • Bow Rollers
      • Chain Stoppers
      • Sailboat Anchors
      • Windlasses
    • Comfort and Mooring
      • Adjustable Cleat For Fender
      • Adjustable Cleat For Lazy
    • Deck Hardware
      • Bailers
      • Bow Fittings & Shroud Plates
      • Cams & Cleats
      • Catches, Latches & Hinges
      • Drain Sockets & Bungs
      • Eye Straps
      • Fairleads
      • Genoa Lead Cars
      • Hatch Covers
      • Pad Eyes & Anchor Plates
      • Pad-pulley
      • Thru-Deck Bushes
      • U Bolts
    • Headsail Handling
      • Furler Spars & Accessories
      • Furler Systems
      • Gennaker Poles
      • Headfoils
      • Jockey Poles
      • Spinnaker Poles
      • Whisker Poles
    • Loops And Textile Connectors
      • Boomstrap
    • Mainsail Handling
      • Boom Vangs
      • Keelbands
      • Mainsail Feeders & Prefeeders
      • Mainsail Luff Systems
      • Mast & Boom Fittings
      • Sailboat Tracks
      • Self Tracking Jib System
      • Sliding Fairlead Systems
      • Sliding Systems
      • T-Tracks
      • Track End Stops
      • Track Slides
      • Tracks
      • Traveler Cars
    • NUB Friction
      • Boomstrap Pulley
      • Loop & Nub
      • Shackle & Nub
      • SPI Nub
    • Rope Clutches
      • Double Clutches
      • Horizontal Clutches
      • Quadruple Clutches
      • Single Clutches
      • Triple Clutches
    • Sailboat Block
      • Block Spars
      • Cheek & Foot Blocks
      • Clew Blocks
      • Double Block
      • Fiddle Blocks
      • Halyard Blocks
      • High Load Blocks
      • Kite Blocks
      • Lashing & Loop Blocks
      • Linked Blocks
      • Mainsheet Blocks
      • Mast Base Blocks
      • OD Blocks
      • Over-The-Top Blocks
      • Pivoting Blocks
      • Quad Blocks
      • Ratchet Blocks
      • Runner Blocks
      • Single Blocks
      • Snatch Blocks
      • Stanchion Mounted
      • Stand-Up Blocks
      • Thru-Deck / Exit Blocks
      • Traveler Block
      • Triple Blocks
      • Upright Lead Blocks
      • Utility Blocks
      • Wire Blocks
    • Sailboat Winches
      • Electric Winches
      • Self-Tailing Winches
      • Standard Winches
      • Winch Handles
    • Sailmaker Hardware
      • Sail Headboards
      • Sail Rings
      • Sail Shackles
      • Sail Track Slides & Slugs
      • Sailmaker Accessories
      • Sailmaker Batten Hardware
      • Sailmaker Hanks
    • Shackles & Clips
      • Bow Shackles
      • C Shackle with Cover
      • C Shackles
      • Clips
      • D Long Shackles
      • D Shackles
      • D Wide Shackles
      • Dogbones
      • Halyard Shackles
      • High Resistance Shackles
      • Hooks
      • J Lock Shackles
      • K Adjustable Shackles
      • Large Open Shackles
      • Ms HL Shackle
      • Shackle Fids & Keys
      • Snap Shackles
      • Spool Shackles
      • Stamped Shackles
      • Swivel Shackles
      • T Shackle
      • Tack Shackles
      • Twisted Shackles
    • Sheaves
      • Acetal Sheaves
      • Alloy Sheaves
      • Aluminium Sheaves
      • Ball Bearing Sheaves
      • Brass Sheaves
      • Delrin Sheaves
      • High Load Sheaves
    • Snaphooks
      • M-T Close Snaphook
      • M-T Sail Snaphook
      • Mf Snaphook
    • Stropes
      • E T-bone
      • E T-close
      • E T-drop
      • E T-sail
      • E-Eye
      • Hoist Strope
      • Textil block
Login / Register
Wishlist
0 Compare
1 item $125.99
Menu
1 item $125.99
Browse Categories
  • Sailboat Hardware
    • Sailboat Block
      • OD Blocks
      • Over-The-Top Blocks
      • Pivoting Blocks
      • Quad Blocks
      • Ratchet Blocks
      • Runner Blocks
      • Mast Base Blocks
      • Fiddle Blocks
      • Halyard Blocks
      • High Load Blocks
      • Kite Blocks
      • Lashing & Loop Blocks
      • Linked Blocks
      • Low Friction Rings And Blocks
      • Mainsheet Blocks
      • Snatch Blocks
      • Stand-Up Blocks
      • Thru-Deck / Exit Blocks
      • Traveler Block
      • Triple Blocks
      • Upright Lead Blocks
      • Utility Blocks
      • Textil block
      • Single Blocks
      • Wire Blocks
    • Sheaves
      • Acetal Sheaves
      • Alloy Sheaves
      • Aluminium Sheaves
      • Ball Bearing Sheaves
      • Brass Sheaves
      • Delrin Sheaves
      • Outhaul Sheaves
      • High Load Sheaves
    • Shackles & Clips
      • Ms HL Shackle
      • Shackle Fids & Keys
      • J Lock Shackles
      • K Adjustable Shackles
      • Large Open Shackles
      • Linked Shackles
      • M HL Shackle
      • Bow Shackles
      • C Shackles
      • D Long Shackles
      • D Shackles
      • D Wide Shackles
      • Snap Shackles
      • Soft Shackles
      • Spool Shackles
      • Stamped Shackles
      • Dogbones
      • Hooks
      • Clips
      • Swivel Shackles
    • Comfort and Mooring
      • Adjustable Cleat For Lazy
      • Adjustable Cleat For Fender
    • Loops And Textile Connectors
      • Boomstrap
    • NUB Friction
      • Loop & Nub
      • Shackle & Nub
      • SPI Nub
      • Boomstrap Pulley
    • Stropes
      • E T-close
      • E T-drop
      • E T-sail
      • E-Eye
      • Hoist Strope
      • E T-bone
    • Rope Clutches
      • Horizontal Clutches
      • Quadruple Clutches
      • Single Clutches
      • Double Clutches
      • Triple Clutches
      • Clutches Accessories
    • Deck Hardware
      • Thru-Deck Bushes
      • Pad Eyes & Anchor Plates
      • Pad-pulley
      • Hatch Covers
      • Deck Organizers
      • Catches, Latches & Hinges
      • Cams & Cleats
      • Bow Fittings & Shroud Plates
      • U Bolts
      • Deck Organizers
      • Pad Eyes & Anchor Plates
      • Eye Straps
      • Bailers
    • Anchoring & Docking
      • Anchoring Ropes
      • Bow Rollers
      • Chain Stoppers
      • Windlasses
      • Sailboat Anchors
    • Sailmaker Hardware
      • Sail Rings
      • Sail Shackles
      • Sail Track Slides & Slugs
      • Sailmaker Accessories
      • Sailmaker Batten Hardware
      • Sailmaker Hanks
      • Thimbles
    • Sailboat Winches
      • Standard Winches
      • Self-Tailing Winches
      • Winch Handles
      • Winch Spare Parts
      • Electric Winches
    • Mainsail Handling
      • Boom Vangs
      • Mainsail Feeders & Prefeeders
      • Mainsail Luff Systems
      • Mast & Boom Fittings
      • Sailboat Keelbands
      • Sailboat Tracks
      • Self Tracking Jib System
      • Sliding Fairlead Systems
      • Sliding Systems
      • T-Tracks
      • Track End Stops
      • Track Slides
      • Tracks
      • Traveler Cars
    • Snaphooks
      • M-T Sail Snaphook
      • Mf Snaphook
      • M-T Close Snaphook
  • Sailboat Equipment
    • Sailing Accessories
    • Sailboat Steering
    • Sailboat Trailers & Dollies
    • Burgees & Flags
    • Sailboat Canvas
      • Yard Covers
      • Sock Covers
      • Spar Bags & Covers
      • Spinnaker Bags
      • Spreader Bags & Covers
      • Spring Board Covers
      • Tiller Covers
      • Travel Deck Covers
      • Travel/Mooring Covers
      • Wheel Covers
      • Winch Covers
      • Mooring Covers
      • Plank Bags
      • Rudder Tiller Covers
      • Sail Bags & Covers
      • Sheet & Store Bags
      • Envelope Covers
      • Fender Covers
      • Hatch Covers
      • Headsail Covers
      • Headstay Covers
      • Mast Bags & Covers
      • Beam & Tramp Covers
      • Boom Tents & Bimini Covers
      • Bottom Covers
      • Bow Covers
      • Cockpit Covers
    • Sailboat Steering
      • Alloy Tillers
      • Aluminum Tillers
      • Pintles & Gudgeons
      • Rudder Blades
      • Rudder Hardware
      • Carbon Fiber Tiller
  • Home
  • Shop
  • About us
  • Contact us
  • Shipping
  • Refunds
  • My account
  • Cart
  • Privacy Policy
  • Terms Of Use
“Ultra Tef-Gel – 12oz (TG-12 oz Cartridge)” has been added to your cart. View cart
Sea Sure Reefing Block 50mm sheave
Click to enlarge
Home Sailboat Equipment Sailing Accessories Sea Sure Reefing Block 50mm sheave
Sea Sure Clew Block 100mm sheave
Sea Sure Clew Block 100mm sheave $470.60
Back to products
Sea Sure Clew Block 50mm sheave
Sea Sure Clew Block 50mm sheave $82.50

Sea Sure Reefing Block 50mm sheave

$82.50

Clew Blocks: Symmetrical both sides

Reefing Blocks: One side is flat so that it can lay flat against the sail.

Our range of clew/reefing blocks are unsurpassed for quality and performance. The bearing system has been engineered to provide smooth running reliability under the most demanding conditions, whilst the aluminium alloy side plates provide strength without adding excessive weight. Both the clew and reefing blocks are available in 4 sheave sizes.

 

Part Number Sheave Diameter mm Max Rope mm Webbing Size mm Boat Size m
04-87RB 42 8 20 7m – 10m
04-88RB 50 10 30 7m – 12m
04-90RB 70 12 30 10m – 16m
04-92RB 100 14 50 14m – 18m
4.87 42 8 20 7m – 10m
4.88 50 10 30 7m – 12m
4.9 70 12 30 10m – 16m
4.92 100 14 50 14m – 18m

Compare
Add to wishlist
Category: Sailing Accessories
Share:
  • Description
Description

Clew Blocks: Symmetrical both sides

Reefing Blocks: One side is flat so that it can lay flat against the sail.

Our range of clew/reefing blocks are unsurpassed for quality and performance. The bearing system has been engineered to provide smooth running reliability under the most demanding conditions, whilst the aluminium alloy side plates provide strength without adding excessive weight. Both the clew and reefing blocks are available in 4 sheave sizes.

 

Part Number Sheave Diameter mm Max Rope mm Webbing Size mm Boat Size m
04-87RB 42 8 20 7m – 10m
04-88RB 50 10 30 7m – 12m
04-90RB 70 12 30 10m – 16m
04-92RB 100 14 50 14m – 18m
4.87 42 8 20 7m – 10m
4.88 50 10 30 7m – 12m
4.9 70 12 30 10m – 16m
4.92 100 14 50 14m – 18m

Related products

ACR Res-Q Whistle
Compare
Quick view
Add to wishlist

ACR Res-Q Whistle

Sailing Accessories
$10.00
Add to cart
Davis Sail Stop  - Round Slug
Compare
Quick view
Add to wishlist

Davis Sail Stop – Round Slug

Sailing Accessories
$10.00
Add to cart
Deck Hatch , Bomar 900 Series
Compare
Quick view
Add to wishlist

Deck Hatch , Bomar 900 Series

Sailing Accessories
$368.00
Add to cart
Dry bag 40 liter Windesign Sailing
Compare
Quick view
Add to wishlist

Dry bag 40 liter Windesign Sailing

Sailing Accessories
$57.70
Add to cart
Harken Spring Cup Del Cam Base (HRHSB2)
Compare
Quick view
Add to wishlist

Harken Spring Cup Del Cam Base

Sailing Accessories
$502.99
Add to cart
Raymarine Wind Vane Service Kit
Compare
Quick view
Add to wishlist

Raymarine Wind Vane Service Kit

Sailing Accessories
$60.00
Add to cart
Ronstan Tell Tails (3 pairs)
Compare
Quick view
Add to wishlist

Ronstan Tell Tails (3 pairs)

Sailing Accessories
$8.73
Add to cart
Shackle Key - Screw driver and Bottle Opener - forged Stainless Steel
Compare
Quick view
Add to wishlist

Shackle Key – Screw driver and Bottle Opener – forged Stainless Steel

Sailing Accessories
$7.30
Add to cart
    • Multiple Warehouse Locations in United States, United Kingdom, Canada, New Zealand, Greece and Australia
    • Email: sales@promarinesupplies.net
    Quick Links
    • Home
    • Shop
    • Contact us
    • About us
    Help
    • Refunds
    • Shipping
    • Privacy Policy
    • Terms Of Use
    • Menu
    • Categories
    • Sailboat Hardware
      • Sailboat Block
        • OD Blocks
        • Over-The-Top Blocks
        • Pivoting Blocks
        • Quad Blocks
        • Ratchet Blocks
        • Runner Blocks
        • Mast Base Blocks
        • Fiddle Blocks
        • Halyard Blocks
        • High Load Blocks
        • Kite Blocks
        • Lashing & Loop Blocks
        • Linked Blocks
        • Low Friction Rings And Blocks
        • Mainsheet Blocks
        • Snatch Blocks
        • Stand-Up Blocks
        • Thru-Deck / Exit Blocks
        • Traveler Block
        • Triple Blocks
        • Upright Lead Blocks
        • Utility Blocks
        • Textil block
        • Single Blocks
        • Wire Blocks
      • Sheaves
        • Acetal Sheaves
        • Alloy Sheaves
        • Aluminium Sheaves
        • Ball Bearing Sheaves
        • Brass Sheaves
        • Delrin Sheaves
        • Outhaul Sheaves
        • High Load Sheaves
      • Shackles & Clips
        • Ms HL Shackle
        • Shackle Fids & Keys
        • J Lock Shackles
        • K Adjustable Shackles
        • Large Open Shackles
        • Linked Shackles
        • M HL Shackle
        • Bow Shackles
        • C Shackles
        • D Long Shackles
        • D Shackles
        • D Wide Shackles
        • Snap Shackles
        • Soft Shackles
        • Spool Shackles
        • Stamped Shackles
        • Dogbones
        • Hooks
        • Clips
        • Swivel Shackles
      • Comfort and Mooring
        • Adjustable Cleat For Lazy
        • Adjustable Cleat For Fender
      • Loops And Textile Connectors
        • Boomstrap
      • NUB Friction
        • Loop & Nub
        • Shackle & Nub
        • SPI Nub
        • Boomstrap Pulley
      • Stropes
        • E T-close
        • E T-drop
        • E T-sail
        • E-Eye
        • Hoist Strope
        • E T-bone
      • Rope Clutches
        • Horizontal Clutches
        • Quadruple Clutches
        • Single Clutches
        • Double Clutches
        • Triple Clutches
        • Clutches Accessories
      • Deck Hardware
        • Thru-Deck Bushes
        • Pad Eyes & Anchor Plates
        • Pad-pulley
        • Hatch Covers
        • Deck Organizers
        • Catches, Latches & Hinges
        • Cams & Cleats
        • Bow Fittings & Shroud Plates
        • U Bolts
        • Deck Organizers
        • Pad Eyes & Anchor Plates
        • Eye Straps
        • Bailers
      • Anchoring & Docking
        • Anchoring Ropes
        • Bow Rollers
        • Chain Stoppers
        • Windlasses
        • Sailboat Anchors
      • Sailmaker Hardware
        • Sail Rings
        • Sail Shackles
        • Sail Track Slides & Slugs
        • Sailmaker Accessories
        • Sailmaker Batten Hardware
        • Sailmaker Hanks
        • Thimbles
      • Sailboat Winches
        • Standard Winches
        • Self-Tailing Winches
        • Winch Handles
        • Winch Spare Parts
        • Electric Winches
      • Mainsail Handling
        • Boom Vangs
        • Mainsail Feeders & Prefeeders
        • Mainsail Luff Systems
        • Mast & Boom Fittings
        • Sailboat Keelbands
        • Sailboat Tracks
        • Self Tracking Jib System
        • Sliding Fairlead Systems
        • Sliding Systems
        • T-Tracks
        • Track End Stops
        • Track Slides
        • Tracks
        • Traveler Cars
      • Snaphooks
        • M-T Sail Snaphook
        • Mf Snaphook
        • M-T Close Snaphook
    • Sailboat Equipment
      • Sailing Accessories
      • Sailboat Steering
      • Sailboat Trailers & Dollies
      • Burgees & Flags
      • Sailboat Canvas
        • Yard Covers
        • Sock Covers
        • Spar Bags & Covers
        • Spinnaker Bags
        • Spreader Bags & Covers
        • Spring Board Covers
        • Tiller Covers
        • Travel Deck Covers
        • Travel/Mooring Covers
        • Wheel Covers
        • Winch Covers
        • Mooring Covers
        • Plank Bags
        • Rudder Tiller Covers
        • Sail Bags & Covers
        • Sheet & Store Bags
        • Envelope Covers
        • Fender Covers
        • Hatch Covers
        • Headsail Covers
        • Headstay Covers
        • Mast Bags & Covers
        • Beam & Tramp Covers
        • Boom Tents & Bimini Covers
        • Bottom Covers
        • Bow Covers
        • Cockpit Covers
      • Sailboat Steering
        • Alloy Tillers
        • Aluminum Tillers
        • Pintles & Gudgeons
        • Rudder Blades
        • Rudder Hardware
        • Carbon Fiber Tiller
    • Home
    • Shop
    • About us
    • Contact us
    • Shipping
    • Refunds
    • My account
    • Cart
    • Privacy Policy
    • Terms Of Use
    • Login / Register
    Shopping cart
    Close
    Sign in
    Close

    Lost your password?

    No account yet?

    Create an Account
    Shop
    Wishlist
    1 item Cart
    My account