Air Hammer, General Duty, Average CFM @ 15 Second Run Time 4, 15.5 CFM, Stroke 3 3/4 In, 2200 Blows per Minute, Min Hose 3/8 In, Air Inlet NPT 1/4 In, Required Pressure 90 PSI, Length 11 3/4 In, Shank Size 0.401 In, Round Shank Type, Pistol Handle, Includes Spring Retainer