Pentair 460737 MasterTemp 400K BTU Propane Gas High Performance Eco-Friendly Heater 400K BTU propane gas high performance Eco-friendly heater Heats up fast so no long waits before enjoying your pool or spa Best-in-class energy efficiency Manual gas shut-off when service is required Eco-friendly MasterTemp is certified for low NOx emission and outperforms industry standards; Measures 36-inch length by 30-inch height by 25-inch width