Sioux Chief HydraRester™ Press-Fit Water Hammer Arrester, 650 Series, 1/2 in Connection, Male Sweat Connection, 350 psi, Lead-Free, Copper, 250 deg F, 8-1/2 in L x 1-3/8 in W, Domestic/Import: Domestic, Additional Information: 5 cu-in Volume, 1-3/8 in W Chamber, 2900 psi Burst Pressure, 1 to 11 Fixture Unit Capacity, Poly Piston, EPDM O-rings, Copper Adapter, Dow-Corning Silicone Compound #111 Piston Lubrication