16mm Single Plain Bearing Block With Brass Sheave. Designed to be lightweight and cost-effective. Ideal for low loaded systems, such as control line bungee take-ups or rope guides. The brass sheave allows this block to be paired with wire as well as offering more durability over the acetal sheave. Plain Bearing Ð The brass 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.