The line fuse, also known as a ceramic fuse, is used to protect your microwave when there is a power serge by shutting down the microwave to avoid damage. If your microwave has no heat, won’t turn on, or the touch pad is not working properly, you may need to replace the fuse. This part measures approximately 1.25” long and is sold individually. Please remember to disconnect power to the microwave before starting the repair. This is a genuine OEM part.