40mm Dynamic Double Swivel Block.

Made from high-strength, lightweight glass-loaded nylon and featuring Allen’s dynamic bearing technology for a high-performance block suitable for keelboats and dinghies.

40mm dynamic blocks are perfect for use on main, jib and spinnaker sheets on dinghies and keelboat control lines.

Bearings Dynamic blocks feature our patented bearing system which uses twin rows of stainless-steel ball bearings running on a stainless-steel rail. The ball bearings are caged for further friction reduction. These features provide a superior load-carrying ability and longevity when compared to other bearing systems.

Swivel Head Featuring a 360-degree swivel head with a 5mm shackle. The shackle is load rated higher than the block, so although it might look small, it’s plenty strong enough!

Swivel Lock This block comes with a swivel lock moulding. The moulding allows the shackle to be locked in 90-degree orientations. It can be removed by undoing the shackle and removing it from the swivel pin.

Becket This block has a specific becket (tying) moulding. The becket allows you to make a purchase system. Ideal for backstay. cunningham, outhaul and vang controls.