CMC CSR Pulley SystemFEATURES The patented locking mechanism in our CSR Pulley is easy to release under load, creating much greater efficiency with the lowering and raising necessary to a confined space rescue. The machined aluminum swivels at both ends of the system eliminate any potential twisting of the lines. This system is also an excellent choice for confined space entry or rope access work where a heavy duty pulley system is desired. Pulleys are UL Classified to