The Allen 30mm Tie-On Dynamic Block offers maximum strength and reliability thanks to its stainless-steel head loop. This loop helps keep the block oriented correctly during use. You can choose to purchase it with or without a soft shackle. The becket, featuring a central rivet and rope-friendly attachment, is perfect for use in a cascade system. Our patented bearing system uses twin rows of stainless-steel ball bearings for superior load-carrying ability and longevity. It is important to properly attach the Tii-On block by threading the rope around the central axle and through the head of the block. For maximum strength, the block should be attached with a crossed or through-threaded line. This will prevent side cheek separation under load. If using a Tii-Shackle, it is recommended to cross the lines whenever possible, unless the application is low-load. See the attached picture for an example of a crossed Tii-Shackle attached to a lacing eye.