Rock Exotica 2.0" Double Omni-Block | P53DThe 2. 0" Omni Block Double features a 51mm (2") sheave diameter. The Omni Block combines a swivel and pulley into one tool, incorporating a unique sideplate that opens while the pulley is still attached to the anchor. Traditionally, a pulley is connected to a swivel by a carabiner. However, the Omni eliminates the need for the carabiner, reducing length and pieces of equipment in the rigging system. The short length of the Omni is important when used