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Description
Ronstan 75mm Mast Base Core BlockProduct Description Ronstan 75mm Mast Base Core Block Features Class leading performance and sleek, contemporary styling Excellent dynamic and high static load performance Less than half the friction of the nearest competitor Durable aluminum alloy cheek plates Central hub hole can be used as a becket take off or tie up point Suits attachment to 14mm (9 16) wide mast collar post Removable 8mm (5 16) clevis pin at head Measurements Sheave 3 in. Max.
Product Description
Ronstan 75mm Mast Base Core Block
Features
Class leading performance and sleek, contemporary styling
Excellent dynamic and high static load performance
Less than half the friction of the nearest competitor
Durable aluminum alloy cheek plates
Central hub hole can be used as a becket take-off or tie-up point
Suits attachment to 14mm (9/16”) wide mast collar post
Removable 8mm (5/16”) clevis pin at head
Measurements
Sheave Ø - 3 in.
Max. Rope Ø - 9/16 in.
Max. Cable Ø - in
Pin Ø - 5/16 in.
M.W.L. - 3000* lb.
B. L. - 6600* lb.
Weight - 8.1 oz.
Product Information
Core Blocks™ are a true all round solution. A tuned 2-stage bearing system provides excellent performance across the full working load range with an integrated thrust bearing feature and the resilience to handle high dynamic or static loads. Acetal sheave, alloy cheeks and stainless fixings complete the durable package. For reliability and a long service life, these blocks are the right choice for sheets, halyards and control line applications for cruising and racing.
Universal Bearing
Dynamic and high static load performance
The Ronstan Universal Bearing incorporates our proven 2-stage bearing system
Stage 1 - Under moderate loads, Acetal ball bearings ensure minimum friction.
Stage 2 - Under heavy loads, where deformation of ball bearings alone would result in increased friction, a sliding Acetal bearing on a polished stainless steel race takes over, maintaining low friction performance.
Additionally the ball bearings are configured to act as a thrust bearing between the sheave and cheeks, preventing the sheave from rubbing on the cheeks and causing friction when the line lead in and out of the block isn’t perfect. Particularly important for cheek blocks.
Alloy cheek plates
Block cheeks are manufactured from the highest quality alloy for maximum strength. Material optimization and the cut-away design minimizes weight and allows easy fresh water rinsing of salt and debris from the bearings. Cheek design has been further styled with flaring at the block throat and reduced gap between the cheek and sheave, minimizing rope wear.
Applications
Ideal for use on mainsheet, spinnaker sheet, vang, halyard and backstay applications on boats up to 14m (46ft).
General applications on larger yachts.
Alloy sheave models are available for use with wire.
Materials
Sheave: U.V. stabilized acetal or anodized aluminum (AW models).
Cheek plates: Aluminum alloy
Ball Bearings: High compression strength carbon black acetal.
Pin: 2205 stainless steel
Features
Measurements
Sheave Ø - 3 in.
Max. Rope Ø - 9/16 in.
Max. Cable Ø - in
Pin Ø - 5/16 in.
M.W.L. - 3000* lb.
B. L. - 6600* lb.
Weight - 8.1 oz.
Product Information
Core Blocks™ are a true all round solution. A tuned 2-stage bearing system provides excellent performance across the full working load range with an integrated thrust bearing feature and the resilience to handle high dynamic or static loads. Acetal sheave, alloy cheeks and stainless fixings complete the durable package. For reliability and a long service life, these blocks are the right choice for sheets, halyards and control line applications for cruising and racing.
Universal Bearing
Dynamic and high static load performance
The Ronstan Universal Bearing incorporates our proven 2-stage bearing system
Stage 1 - Under moderate loads, Acetal ball bearings ensure minimum friction.
Stage 2 - Under heavy loads, where deformation of ball bearings alone would result in increased friction, a sliding Acetal bearing on a polished stainless steel race takes over, maintaining low friction performance.
Additionally the ball bearings are configured to act as a thrust bearing between the sheave and cheeks, preventing the sheave from rubbing on the cheeks and causing friction when the line lead in and out of the block isn’t perfect. Particularly important for cheek blocks.
Alloy cheek plates
Block cheeks are manufactured from the highest quality alloy for maximum strength. Material optimization and the cut-away design minimizes weight and allows easy fresh water rinsing of salt and debris from the bearings. Cheek design has been further styled with flaring at the block throat and reduced gap between the cheek and sheave, minimizing rope wear.
Applications
Materials
Shipping Notes
- Free Standard Shipping on $100+ Orders to the USA.
- Except Preorder products are shipped in 48 hours.
- Delivery to the USA:
- Standard Shipping : 3-10 business days
- If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
- We offer a 30-day return/exchange service after receiving.
- Final sale items are not eligible for returns or exchanges.
- To process your return/exchange, please contact us at [email protected]
- Please click here for more details>>> Return & Exchange Policy
4.2 ★★★★★
Based on 15 reviews
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Product Reviews
★★★★★ 5
Best plug if you are traveling to France or Europe
Style: Type C/G/A-Most Countries-3FT
If you ever need a European plug, this is the one to get. I took it with me to France for a whole month and it was a life saver. I was able to plug all my electronics and also have no issues with the conversion of watts. Now that I have it I take it with me anytime I travel to Europe.
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Reviewed in the United States on January 31, 2026
★★★★★ 5
Perfect, travel accessory
Style: Type C/G/A-Most Countries-3FT, Style: Type C/G/A-Most Countries-3FT
Perfect travel item!
This was so useful two of us were able to charge our phone at the same time and our extra battery pack. Perfect travel item should be a staple.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 22, 2026
★★★★★ 5
Great Buy
Style: Type C/G/A-Most Countries-3FT
Bought for trip to Italy. The long cord worked great as I had several things to charge and the side tables weren't big enough. This reached the floor and nothing was falling off tables. The plug fit snugly in the socket which was key as they tend to be loose there. Don't take your own hair dryer or curling iron, they burn out from the amperage there.
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Reviewed in the United States on April 6, 2026
★★★★★ 4
Good product
Style: Type C/G/A-Most Countries-3FT
A little bulky but worked great for my trip to Italy.
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Reviewed in the United States on March 27, 2026
★★★★★ 5
Fantastic adapter for international travel
Style: Type C/G/A-Most Countries-3FT
This adapter worked as intended when needing to charge devices in Europe. The adapter was easy to attach to the plug and the cord length came in handy for sockets that were in hard to reach locations. The only thing is it does take up some space in luggage, so make sure to account for that. Would definitely recommend for international travel.
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Reviewed in the United States on April 30, 2026