This is a 50mmD Nylon pulley mounted on a strong aluminium frame for clamping to a bench top (or any flat surface). The maximum clamping thickness is 25mm. When clamped, the side of the pulley is parallel to the surface of the bench. The clamp screw has a protective pad on the tip so the bench surface is not damaged. This style of pulley is normally used for taking a cord close to the table top and passing the cord back over the table top.
