The Microwave Mounting Bolt is an OEM replacement part specific to Samsung over-the-range microwaves. It is one of the fasteners used to securely attach and mount the microwave to the upper kitchen cabinet.  The bolt measures approximately 4” long. Causes of a bad mounting bolt can include rust or corrosion from prolonged exposure to moisture, wear and tear over time, or damage due to over-tightening or improper installation. Symptoms of a faulty or damaged mounting bolt include: The microwave pulling away from the wall or becoming loose over time Noisy or creaking sounds emanating from the mounting area  Suspected mounting points failing building code requirements This OEM Samsung part is also compatible with GE, Whirlpool, LG, and some Frigidaire over-the-range microwave models.DE60-20066A (AP4219712) replaces 2079902, PS4226718.