The Kwik Charge® charging unit accepts liquid refrigerant from the cylinder and discharges into low side of the system. Liquid charging is required when using R-410A and other blended refrigerants. Internal metering element reduces liquid flow to a level below capacity of compressor. This assures a safe, fast charge without endangering the compressor. A built-in ball check valve automatically opens when drawing a vacuum to assure rapid, unrestricted evacuation. Can be used with all fluorinated hydrocarbon refrigerant systems. Imperial®, 535-C, Liquid Low Side Charger, Refrigerant, For Use With: Fluorinated Hydrocarbon Refrigerant System, Specifications: Both Ducted and Ductless, Import