1 hour gas timer twists to turn on and off for gas glow up to one hour. The cast body makes for easy install. 1/2" Female NPT. 1000,000 MAX BTU Capacity. Maximum working pressure: 1/2 P.S.I.G. 3 Mounting holes. It is an easy-to-use timer that provides precise control over gas flow, with a durable design that can handle up to 1 million BTUs at 1/2 P.S.I.G. of pressure.