The Tii design incorporates a special stainless steel insert in the head which improves the stability and durability of the blocks.

Allen 40mm Dynamic Blocks are built using a light weight composite cheek with a rope friendly, light weight stainless steel anchor strap and patented Allen dynamic bearing system. The range features a large central hole, which provides great options for tie-on beckets and is available with a variety of accessories, making it the suitable choice for demanding applications. These include dinghy mainsheets, jib and spinnaker sheeting systems as well as keelboat control lines.