This thermostat cavity is a genuine General Electric part, sold individually. It can be used as a replacement part for a microwave. This thermostat cavity regulates the temperature and power of the appliance so that it can properly heat up food and other items inserted into the appliance. The thermostat cavity is made out of durable gray metal.The thermostat cavity of a microwave might have to be replaced if it exhibits either of the following symptoms: the exhaust fan of the microwave is malfunctioning, or the microwave does not run or runs for under ten seconds before stopping. If either of these symptoms occur, the thermostat cavity should be removed and replaced by this genuine OEM replacement part before using the microwave again. Remember to wear work gloves while inspecting the thermostat cavity and while conducting a replacement. It is a relatively complicated replacement that will require several special tools.This is an OEM part sourced directly from the manufacturer. It is sold individually. This thermostat cavity is compatible with General Electric brand microwaves.WB27X10909 (AP3994059) replaces 1262954, AH1481222, EA1481222, PS1481222.