About the watts 1 / 2 lf15m2a water pressure regulator, 1 / 2" hammer arrestor lead free the watts 1 / 2 lf15m2a water pressure regulator, 1 / 2" hammer arrestor lead free can be used in commercial and industrial applications to control water pressure shock and prevent water hammer conditions. The lf15 consists of a copper body, EPDM seals and O-rings, brass piston and cap and NPT threaded brass hex adapter. Optional 15ak adapters available. Series lf15 is factory air charged and is not rechargeable. It can be installed in new or existing plumbing systems in concealed locations with a standard pipe tee in any angle. Series lf15 is ideal for commercial dishwashers, clothes washers and quick closing faucets. ASSE and ANSI approved, PDI certified and IAMPO listed.