Ever wish you could have more hot water but didn?t want a bigger, bulkier, heavier water heater? Introducing the Atwood XT water heater-the intelligent way to deliver more hot water. Provides the equivalent of 16 gallons of hot water in a 10 gallon size by heating cold water to a hotter temperature and then mixing it with more cold water through an already installed mixing valve on the rear. The result is 50% more hot water! Easily installed in the same cut-out dimension of an existing Atwood 10 gallon water heater. Features pre-installed winterizing by-pass kit. Cutout dimensions: 15-1/2"H x 16"W x 20-3/4"D.