This 1/2 in. lead free water hammer arrestor provides economical and effective single fixture protection used in residential or domestic water applications such as dishwashers washing machines and quick closing faucets. It is designed to control the water pressure shock and prevent water hammer conditions that are damaging to pipes and appliances. It consists of a stainless-steel top and lower chamber sealed-in diaphragm which flexes to absorb the shock and a lead-free brass hex adapter for easy installation. This may be installed in new or existing plumbing systems vertically horizontally or at any angle and should be installed as close to the shock source as possible with one unit for each hot and cold-water line up to 150 psi (10.6 BAR) working pressure. It is factory air charged at 30 psi (207 kPa) and is easily rechargeable with a standard tire valve connection and air-tight sealing cap. 1/2 in. NPT connection for easy installation Unit is factory pre-charged to 30 psi (207 kPa) Easily rechargeable with standard tire valve Molded diaphragm with a special thermo plastic coating to prevent rust Single fixture protection Can be installed in new or existing plumbing systems Proposition 65 Information WARNING: This product can expose you to chemicals including lead which is known to the State of California to cause cancer and birth defects or other reproductive harm.