The A.O. Smith R2VR-180E 2-Chamber Tankless Electric Water Heater is a compact and efficient water heating solution for your home. With a power source of corded electric and battery, this tankless water heater offers an energy efficiency rating of A+++ - E. The gray-colored unit features a 3/4 inch NPT water connection, adjustable thermostat, and digital display for easy operation. This model is designed for instantaneous (tankless) heating with a voltage of 240V and an amperage of 180A. With features such as automatic shut off, variable temperature control, and a compact design, the A.O. Smith R2VR-180E is a reliable choice for your space-saving water heating needs.