Plain Bearing – The acetal sheave spins around the central axle. This type of bearing has a long lifespan and is very low maintenance. Lightweight Strap - The body of this block is formed in stainless steel for a lightweight yet robust frame. Cheek Block - Designed to be fixed to a flat surface. Ideal for leading lines along a deck, into a cleat or around corners. Held in place by two screws. One screw through the middle of the sheave and the other through the top rivet.