SunEarth DrainPack Hot Water Station is a pre-built tank assembly for simplified installation of a drainback type solar hot water heating system. All items are pre-mounted and plumbed to a SunEarth 120HE solar storage tank. Includes storage tank with dual wall heat exchanger, 7.2 gallon copper drainback tank, circulator pump, digital controller, domestic water expansion tank, domestic outlet mixing valve, bypass valves, and plumbed relief valve drains.