RAYPAK  336,000 BTU Millivolt Pool / Spa Heater, Natural Gas, Corrosion-Resistant Headers, High-Wind Resistance, For Elevations of  0 - 2,000 Feet 

Deminsions:: 26.0" wide x 28.0" deep x 40.0" high  

Weight: 230 lbs.

3/4" gas connection / 2" water connection

The Raypak Millivolt (pilot light) gas heater comes with a mechanical thermostat control. This control allows you to set your pool or spa temperature at your favorite setting.  Just set it, and forget it! Truly simple.  With over 50 years in designing and building gas heaters, Raypak has put all that experience into its newest heater design. No need for fans to combat drafting problems, the Raypak  was designed for outdoor installations with its exclusive low profile design. It is so thoughtfully and carefully designed it actually protects itself from the things that tend to stifle ordinary pool and spa heaters: falling leaves, wind, airborne debris, rain, downdrafts, updrafts, sleet, snow, etc. In fact it is so efficiently designed it ensures uninterrupted heating performance regardless of all but the most extreme weather conditions. Built Raypak tough. Built to last.