The Microwave Halogen Light Bulb is a replacement accessory for the exterior bulb that mounts on the bottom of the appliance to illuminate the cooktop. Note that if the threads of the current light bulb are corroded, you may also need to replace the socket. This 40-watt bulb with small screw-in base is an accessory that can be used across several brands; check to see if your model number is compatible. Replacing this accessory will require basic hand tools, minor disassembly of the microwave and novice repair experience. You must unplug the microwave or shut off the house circuit breaker for the appliance before installing this light bulb.