20mm Single High Load Dynamic Block.High load blocks feature a stainless-steel sheave. This upgrade offers even faster rolling speeds, higher working loads and lower friction when compared to the standard acetal sheave. The stainless-steel sheave allows the block to be paired with both rope and wire.Ideal for use in higher loaded applications in dinghies, windsurfing, kitesurfing and anything else that runs smaller diameter lines.  Bearings Ð Dynamic Blocks feature our patented bearing system which uses twin rows of stainless-steel ball bearings running on a stainless-steel rail. This provides a superior load-carrying ability and longevity when compared to other bearing systems which run on a plastic rail. Ultra-Strap Ð Our patented Ultra-Strap is used in our 20, 30 & 40mm Dynamic blocks. The Ultra-Strap is unique when compared to other designs because of its coining process. This process strengthens the strap, making it more reliable and hard-wearing as well as making it much more rope friendly than other designs. The Ultra-Strap was the first marine industry block designed to work specifically with a rope attachment. Becket Ð Our 20 & 30mm blocks offer a large central rivet which not only reduces the overall weight but also offers a rope friendly attachment, perfect as a tie-off point when being used in a cascade system.