The Allen 30mm Plain Bearing Multi Function Block is perfect for take-up and non-friction systems. For optimal results, we recommend using our Dynamic block range instead. This recycled plastic block has a multi-function head to attach swivel, fork, and cheek adaptors, as well as to rivet to double and triple ultra-straps. The acetal sheave in the plain bearing rotates around the axle, providing a durable and low-maintenance option. Additionally, the hole through the middle of the block can be used as a becket for tying off.