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.