This Avantco 17819015 defrost heater is a direct replacement for the one that came with your Avantco worktop or undercounter freezer. It is a vital part of your unit to help melt accumulated frost off your unit's evaporator coil surfaces and warm the drain pan, allowing the condensation to drain without refreezing. Be sure to replace a worn or broken part promptly to keep your unit operating efficiently. It's compatible with Avantco ZWT-36F and ZUC-36F series 36" worktop and undercounter freezers.