The Hardware Kit is an OEM part for Whirlpool microwaves. This kit includes essential mounting brackets, screws, and other fasteners required for the proper installation and secure mounting of the microwave, either over the range or within cabinetry. Causes of a bad hardware kit can include wear and tear over time, exposure to moisture, or damage due to mishandling or incorrect installation.   Symptoms of a bad hardware kit include: Loose or unstable microwave installation Rattling or vibrating noises during operation Difficulty in mounting or securing the microwave Visible rust or damage to screws and brackets This OEM Whirlpool part is also compatible with Maytag, KitchenAid, Jenn-Air, Amana, Magic Chef, Admiral, Norge, Roper and some Kenmore models.W10821385 (AP5989587) replaces 8206614, W10811221, 4383482, PS11730898, W10728970.