Pentair PacFab 461058 125K BTU MasterTemp Propane Gas Heater with Cord High-performance, affordable heating with premium features 82% energy efficiency is highest in its class 1.5" plumbing  ideal for smaller bodies of water up to 15,000 gallons Pre-mixed combustion technology for ultra-fast heat-up Rotating digital display - the first in its price category - provides fast, easy access for programming and monitoring