P/N: 460734 Pentair MasterTemp Heater Low-NOx Natural Gas  Input: 300,000 BTU Heater Size: 32.61 inch W x 23.02 inch D x 28.15 inch H Vent Diameter: Works for vent sizes 6-10 inch, Outdoor: Stackless Outdoor Venting System Ignition: Hot Surface Ignition Thermostats: 2 (1 for Pool / 1 for Spa) 6 inch clearance on all sides needed for proper operation. Master-Temp Heaters offer all the efficiency, convenience, and reliability features you want in a pool heater, plus a lot more fast heat-up, compact design, super quiet operation, easy to use, and Eco-friendly An Eco Select Choice: Master-Temp Heaters offer best-in-class energy efficiency. Plus, they are certified for low NOx emissions, making them Eco-friendly favorites. No matter what you're seeking in your swimming pool heater, Master-Temp measures up. Compare this list of features to any other and you'll see why Master-Temp is setting a new standard for total value. Approved for installation on combustible surfaces. Very compact design for such a high performance heater allows for smaller overall equipment pads that won't intrude on your poolscape. A fully pre-mixed system with a highly efficient air and gas mixture lets MasterTemp heat up fast. No long waits before enjoying your pool or spa. Compare energy efficiency ratings and you'll find MasterTemp at the top of the list. Comfort and economy can go together. The easy-to-view, rotating digital display places controls front and center, no matter how MasterTemp is positioned on your equipment pad. MasterTemp is engineered for super-quiet operation and won't intrude on your poolside leisure time. A tough, rustproof composite exterior handles the heat and weathers the elements. With a hot surface ignition (no pilot light) and pushbutton, digital controls, MasterTemp is as easy to operate as your home heating system. Plus, user-friendly indicator lights make system operation and monitoring a snap. Eco-friendly, MasterTemp is certified for low NOx emissions and outperforms industry standards. Safe operation is assured through a series of features, including; a water pressure switch that senses the pump is running to prevent overheating; high limit switches assure the heater turns off if water temperature exceeds factory-set limits; manual gas shut-off when service is required; stack flue sensor also guards against overheating. Features: 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 Rotating digital display allows for easy viewing Tough, rustproof exterior handles the heat and weathers the elements