Maid O'Mist 1/8" Angle Steam Vent with .070 vent size. This vertical mounting vent is suitable for radiators near boilers and in warm rooms, such as second-floor radiators. Its venting capacity is equivalent to four ordinary air valves, ensuring efficient air release. The self-adjusting thermostatic control and float prevent water escape, reduce radiator noise, cut fuel consumption, assure even heat distribution, and lower operating costs.