Rated at 16 kilowatts at 240 Volts at a Max of 66 Amps. An optional sub-panel is available from us which is supplied with two, two pole 35 Amp breakers. The Sub-panel is normally wired to the main panel using a 70 Amp breaker and four gauge wire directly to the sub-panel. The sub-panel contains two dual35 Amp breakers for easy hookup. Note that normally 8/2 ga. wires from each breaker leads to the tankless. This is designed to keep your installation to Code. Please check your community's electrical Codes for proper installation of your heater. We suggest using licensed, qualified individuals for all tankless water heater installations. With a one year Warranty on the replaceable heating elements, three years on the electronics and a lifetime on the water carrying parts, this may very well be, the last water heater you ever need. CSA 22.2 approved for use in Canada, ETL listed UL #834 listed and #499 UL Compliant for your safe use in the USA