Web block, sheave 70, SWL 3500 kg. These small and light blocks are the best solution for very high loads when sliding is not important. The very small sheave is fitted with a Composite Fibre bushing. The one piece frame is made for line connection. The 3 blocks (D=30, 40 and 55 mm) give an 8 to 1 system. This system is specially designed for the backstay or the boom-vang.