Schaefer hinged half-moon base blocks provide a strong and smooth option for leading your halyards and control lines to the cockpit. Choose from four different models, all featuring a heavy duty stainless steel cage, polished and buffed to a mirror finish. Sheaves are machined aluminum and run on our self-lubricating Nomex®/Teflon® bearing. UC models incorporate Delrin® ball bearings for additional friction reduction. Model #32-17 has an especially narrow profile to allow more leads to be placed side by side; its bushed aluminum sheave accepts up to 3/8" wire or rope