Maid O Mist Push Button Manual Vent, the easiest way to manually vent a radiator without a key, coin, or screwdriver. Simply push the insulated cap to release trapped air. Suitable for vertical or horizontal mounting, it features a 1/8" I.P. male connection, up to 50 lbs pressure, and measures 1-5/8"x9/16". Ideal for tight spaces where vents requiring a key or coin are not practical.