Description: CMI stainless steel blocks are a staple in the arborist community. Engineered to take on the most demanding rigging jobs, the block cheeks are made from high strength stainless steel to give you years of service. Aluminum alloy bushings and sheaves are supported by stainless steel axles. Upper bushing is easily accessed by a no-slip nob, and it is captive, so you won't loose it. Sheave is 3 inch in diameter and is supported by a sintered bronze bushing. Cheek plates are broad enough to protect lines during use and polished to a shine. Blocks have a work load limit WWL of 5,600 lbs. at a 5 TO 1 ratio.