22″ Radius blocks are used instead of full diameter blocks. Lightweight and durable, they rotate freely from a vertical to a horizontal position when used on a corner structure. Accepts wire up to 2″ diameter. 7″ diameter sheaves available. DNRB3222-AL Aluminum, DNRB3222-LS, Urethane Lined, and DNRRB3222-DI Ductile Iron. We generally stock common parts.