These are fitted to use with Our RockPro 50mm Hydraulic Splitters. Both the supply and return line are put into the Remote Valve, continued through the Hydraulic circuit and attached to the splitter in the rock. The operator will then be able to activate the equipment without touching the splitter itself. This accessory is IDEAL when breaking larger unstable rocks that you don't want your guys standing on when it breaks, especially if the boulder is on a slope.