This multi-use wide throat and Utili-Sheave is perfect for passing a variety of line, connecting links and terminations. Hardening manganese steel sheaves maximize wire rope and sheave life. The R-6, R-8 & R-10 are equipped with tapered roller bearings for long life in higher line speed applications. R-4 feature straight roller bearings to minimize size. Binding between sheave and block side prevents wire rope from binding.