SKU: 45163844221

Ronstan Series 40 Ball Bearing Orbit Block - Single - Becket - Cleat - Swivel Head

Sale price$89.08 Regular price$98.98
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Description

Ronstan Series 40 Ball Bearing Orbit Block - Single - Becket - Cleat - Swivel HeadSeries 40 Ball Bearing Orbit Block Single Becket Cleat Swivel Head Features: Ultra Lightweight Low friction 2 stage Orbital ball bearing system Highest working load in its class Low profile and compact High performance cleating Lightweight Kilogram for kilogram of working load, BB and RT Orbit Blocks are the worlds lightest. The unique orbital design allows the bearing to only be in the active areas of the floating sheave. This minimizes the mass of

Series 40 Ball Bearing Orbit Block - Single - Becket - Cleat - Swivel Head

Features:

  • Ultra Lightweight
  • Low friction 2-stage Orbital ball bearing system
  • Highest working load in its class
  • Low profile and compact
  • High performance cleating

Lightweight

Kilogram for kilogram of working load, BB and RT Orbit Blocks™ are the world’s lightest. The unique orbital design allows the bearing to only be in the active areas of the floating sheave. This minimizes the mass of the inactive return race and hub.

Weight and bulk are further reduced in the different block configurations. The ball bearing single and becket block has a through-sheave becket arrangement. The result? The lowest weight possible.

Multi-sheave blocks have only single intermediate cheeks and an ultra-light and efficient head arrangement. This gives a 30% weight saving advantage over the nearest competitor. Other brands just link together their single blocks. This results in unnecessary double cheeks between each sheave, held together by a heavy steel channel across the top of the block.

Highest Working Load In It's Class

The orbital ball-bearing arrangement gives the largest possible bearing race diameter. This maximizes load performance. The proven Ronstan 2-stage bearing system features high compression grade acetal ball bearings and a secondary full-contact bearing. This gives minimum friction across the full working load range.

The floating sheave and bearing system is supported by a fiber-reinforced load frame. The design was computer modeled to be stress optimized.

Applications:

  • Mainsheet systems on spinnaker sheet on dinghies to 5m (16ft)
  • Spinnaker sheets on dinghies, sportsboats and small keel boats to 5m (16ft)
  • Halyard, vang and backstay applications on boats to 8m (26ft)
  • Control line applications on larger yachts

Materials:

  • Ball Bearings - High compression strength carbon black Acetal.
  • Stage 2 Bearing - Glass fibre reinforced, MoS2 impregnated Nylon
  • Frame/Cheeks - Toughened, glass fibre reinforced Nylon
  • Sheave - Carbon fiber reinforced, PTFE impregnated Nylon

Manufacturer Part Numbers: RF45130
GRP:WRO
Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. 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
SKU: 45163844221

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Vivian
Carnegie, US
★★★★★ 4
Noticeable Support for Calm and Clarity
Size: 90 Count (Pack of 1), Size: 90 Count (Pack of 1)
This magnesium L‑threonate supplement has been a great addition to my daily routine. The capsules are easy to take, gentle on my stomach, and I’ve noticed a clearer, more focused feeling throughout the day. It also brings a nice sense of calm in the evenings without making me groggy. The formula feels clean and well made, and it fits effortlessly into a wellness routine. If you’re looking for a reliable magnesium option that supports relaxation and mental clarity, this one is a solid choice.
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Reviewed in the United States on January 29, 2026
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Cassie
Phoenix, US
★★★★★ 5
Highly recommend for sleep, mood, mental health
Size: 90 Count (Pack of 1)
I recently re-discovered this supplement, and I'm buying extras left and right and recommending to everyone I talk to. I've been working on increasing my HRV and supporting my nervous system, and the L-threonate is a rockstar for that. I was taking glycinate for a few months, and I found an old bottle of this one and added just 2 capsules, and the effect on my sleep was immediate. Way better than melatonin. My Fitbit is tracking much lower restlessness and more deep sleep, and I actually wake up feeling refreshed ?? and before my alarm, even! I'm noticing lower anxiety and an overall better mood, and it's only been 4 days. This bottle definitely holds its value, and the price is good, especially if I can get these benefits with just the 2 caps and not 3.
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Reviewed in the United States on April 1, 2026
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Studying & doing nutrition for over 60 yEARS
Massapequa, US
★★★★★ 5
Big winner for helping BETTER SLEEP
Size: 90 Count (Pack of 1)
Life Extension is top of the line on most things they have. also pricier than most, but I buy three items for them regularly for many years. This Neuro-Mag with L-Threonate is excellent for boosting better sleep. This is a newer addition to their line. I also suggest trying their Mult-B complex and their B-12 elite (sublingual) On nearly all items, their quality control is near THE TOP of all suppliers. They also have supported vitamin and supplement research on my items over the last 40 years
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Reviewed in the United States on May 29, 2026
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kacy
San Leandro, US
★★★★★ 5
Energy and Clear Thinking
Size: 90 Count (Pack of 1)
Great product. I use various forms of magnesium for different things . This form was suggested for clearer thinking and energy, and it delivers! I use it in the AM and it helps keep me energized I do think it varies by person how it affects you though as some folks get drowsy w/ it. Just a heads up to test on a weekend perhaps. I won't be without it now!
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Reviewed in the United States on April 5, 2026
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Jason K
Chelsea, US
★★★★★ 3
Capsules Are Too Large and Have a Strong Plastic Smell
Size: 90 Count (Pack of 1)
I’ve purchased this product twice, but the capsule design is a big downside for me. The capsules are very large and difficult to swallow. On top of that, there is a noticeable plastic-like smell from the capsules, which is quite distracting and unpleasant. It makes taking them every day uncomfortable. The product itself may work as intended, but the capsule size and odor seriously affect the overall experience. I wish they would improve the capsule material or offer a smaller or odor-free option. If you are sensitive to smells or have trouble swallowing large capsules, keep this in mind before buying.
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Reviewed in the United States on February 3, 2026

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