Petzl's Gemini Double Prusik Pulley lets you set up a variety of hauling systems with either one or two ropes. It features sheaves mounted over sealed ball bearings for smooth efficiency, and the unique side plates work with the auxiliary attachment to accommodate complex capturing systems or simple Prusik hitches for lighter hauls. Despite its double dimensions, the Gemini remains small and light enough for any big wall, alpine, or mountaineering endeavor.