Push Button Manual Vent, Provides The Easiest Way To Manually Vent A Radiator, You Don't Need A Key, Coin Or Screwdriver, All You Have To Do Is Push On The Insulated Cap To Release Trapped Air, Vertical Or Horizontal Mounting, 1/8" I.P. Male Connection, Up To 50 LBS Pressure, 1-5/8" x 9/16".