Product Description: Use in furnaces: Duo-Therm . Hydro-Flame . Suburban works in ?Park Model? furnaces which use a 24V AC ignitor board. This board also has the same great features as the other Universal Ignitor Boards. Includes a fuse on the board to protect the board?s 24V circuits from short circuit damage and a green light to show power to the board and a red light to indicate power to the gas valve. For 24V AC furnaces only. Board dimensions: 3-3/7" x 5-1/10".