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 NFPA 1983 – General Use. System includes: 1/2? Static-Pro Lifeline (1 x 200?), CSR Pulley, CSR Double Pulley, ProSeries Aluminum Manual-Lock Carabiner (2), and #3 Rope Bag.