This 30mm Allen Dynamic Double Block Tie On Hl features a stainless-steel loop at the head for maximum strength and reliability. The high load stainless-steel sheave allows for faster rolling speeds, higher working loads, and lower friction compared to the standard acetal sheave. When attaching the block, be sure to use the correct method for maximum strength, such as feeding the rope through the central axle and head of the block. For further fitting advice, please contact us. The central rivet also serves as a rope-friendly attachment for use in a cascade system. Our patented bearing system using twin rows of stainless-steel ball bearings on a stainless-steel rail provides superior load-carrying ability and longevity. Please note that this block does not come with a Tii-shackle. See images for proper installation.