Allen Brothers 20MM Dynamic Single Multi Function
Availability: Please contact us to confirm availability or discuss item replacements. Please note that certain products may have an estimated arrival time of 30 days and are not available for expedited shipping.
Pickup available at 1830 East Interstate 30
Usually ready in 24 hours
Shipping and Delivery
Free shipping for orders of $98 or more (US Continental)
- Free shipping for orders of $750 or more (International)
- Add 3 business days to the standard shipping time for USPS deliveries.
- UPS and FedEx Ground usually take 2 to 5 business days for in-stock orders.
- UPS and FedEx deliver on Saturdays only for Friday overnight shipments, which may incur an extra
charge. - Orders that apply for free shipping will be delivered between 8 and 10 business days.
- International customers will be responsible for any applicable import duties,fees, or taxes.
- Oversized items like whisker poles, spinnaker poles, and tracks over 7 feet require freight shipping, with an estimated cost of $500 depending on the destination.These orders must be delivered to a
commercial address, such as a marina, yacht club, or boatyard where your sailboat is located.
A recipient must be present to sign for the delivery upon arrival,For more info, Click Here.
Allen Brothers 20MM Dynamic Single Multi Function
20mm Single Dynamic Multi Function BlockThe 20mm Single Multi Function Block is a versatile foundation block used across a wide range of configurations within the 20mm range. Featuring a modified head design compared to the standard A2020, it is engineered to accept a variety of attachments and serves as the base for multiple single, double, and triple block assemblies.
Key Features- Multi-function head designed to accept swivel, fork, and cheek adaptors
- Base block used in the A2021F, A2021HK, A2021SC, and all double and triple variations
- Engineered for integration with double and triple Ultra-Strap assemblies
- Compact, lightweight, and durable construction
- Patented Dynamic Bearing System with twin rows of stainless-steel ball bearings running on a stainless-steel rail for superior load capacity and longevity
- Integrated Becket with a large central rivet, providing a lightweight and rope-friendly attachment point for cascade systems
- Ideal for applications requiring flexibility, modularity, and smooth, low-friction performance
Technical Description
| Accessories | None |
| Bearing type | Dynamic |
| Breaking load | 350 kg |
| Configuration | Single |
| Height | 12 mm |
| Length | 35 mm |
| Maximum line diameter | 6 mm |
| Maximum working load | 115 kg |
| Sheave diameter | 20 mm |
| Width | 20 mm |
| Weight | 14 g |
Allen Brothers 20MM Dynamic Single Multi Function
20mm Single Dynamic Multi Function BlockThe 20mm Single Multi Function Block is a versatile foundation block used across a wide range of configurations within the 20mm range. Featuring a modified head design compared to the standard A2020, it is engineered to accept a variety of attachments and serves as the base for multiple single, double, and triple block assemblies.
Key Features- Multi-function head designed to accept swivel, fork, and cheek adaptors
- Base block used in the A2021F, A2021HK, A2021SC, and all double and triple variations
- Engineered for integration with double and triple Ultra-Strap assemblies
- Compact, lightweight, and durable construction
- Patented Dynamic Bearing System with twin rows of stainless-steel ball bearings running on a stainless-steel rail for superior load capacity and longevity
- Integrated Becket with a large central rivet, providing a lightweight and rope-friendly attachment point for cascade systems
- Ideal for applications requiring flexibility, modularity, and smooth, low-friction performance
Technical Description
| Accessories | None |
| Bearing type | Dynamic |
| Breaking load | 350 kg |
| Configuration | Single |
| Height | 12 mm |
| Length | 35 mm |
| Maximum line diameter | 6 mm |
| Maximum working load | 115 kg |
| Sheave diameter | 20 mm |
| Width | 20 mm |
| Weight | 14 g |


