The MRCOOL UHK05 Universal R-454B Air Handler Supplemental Heat Kit is a 5 kW electric heating accessory designed to provide additional warmth when a heat pump requires supplemental heating capacity. The kit uses electric resistance heating elements to generate heat and works with compatible MRCOOL air handlers in R-454B HVAC systems. https://www.partshnc.com/mrcool-5kw-universal-heat-kit-uhk05