Petzl Gemini PulleyCompact double pulley for setting up progress capture systems of high mechanical advantage. Special side plates designed for use with a Prusik friction hitch in progress capture systems Parallel mounted sheaves and auxiliary attachment point for creating different types of hauling systems Sheave mounted on sealed ball bearings for excellent efficiency Compact and lightweight Rope compatibility: 7 to 11 mm Sheave diameter: 25 mm Ball bearings: yes