#MT0500EN09CBPN Pentair Commercial Megatherm 500 BTU Cupro Nickle, Outdoor High Performance Electronic Ignition Pool Heater Natural Gas500 BTU Cupro Nickle Heat Exchanger MegaTherm High Performance Electronic Ignition Heaters...Powerful, efficient, and reliable, MegaTherm pool heaters are designed for commercial, institutional and large residential pools where economical performance and rapid heat-up are required. Available in indoor and outdoor models in both natural and propane. MegaTherm is design certified to the ANSI Z21.56 Standard for Gas-Fired Pool Heaters. (Outdoor 500-1825 units are certified for use without the addition of a draft diverter or external vent. Indoor units incorporate a built-in draft diverter and require only vent piping.) Salt water models (500-1825) are available with cupro-nickel alloy heat exchanger tubes and bronze headers and header covers.Features:Electronic ignitionBuilt-in draft diverter (indoor models) simplifies installationIntegral pump assures proper water flow (Models 500-1825)Automatic gas valveStainless steel burners, with slide-out burner tray for easy maintenance and long life (Models 500-1825)High temperature refractory firebox liner to 2000° F for greater efficiencyEasy-to-service header flangesCorrosion-resistant glass-lined or bronze headersCSD-1 and other options available. Contact factory for part numbershttps://www.pentair.com/en-us/products/business-industry/commercial-pool-products/commercial-pool-heaters/-megatherm--high-performance-electronic-ignition-heaters.html