The 30mm Dynamic Block with Fiddle And Cleat from Allen is a top choice for applications that require constant sheave movement. Its lightweight design makes it ideal for vang systems, while the allenite cam cleat with over fairlead provides reliable control. With a built-in swivel pin, this block can easily rotate for changing pulling forces. The patented bearing system with twin rows of stainless-steel ball bearings ensures superior load-carrying ability and longevity. The addition of a secondary fiddle allows for an inline purchase system, and the removable clevis pin allows for easy attachment or release of a spliced rope, creating a 4:1 purchase system.