The Shelf Support is an OEM part for Frigidaire countertop microwaves. It holds and stabilizes shelving inside the microwave cavity during operation.  Symptoms of a faulty shelf support include: Loose or detached shelves that cannot maintain placement   Difficulty positioning shelves at desired height levels Scrapes or dents on interior microwave walls from shelf movement Gaps or spaces where shelf legs do not sit securely   Causes relate to typical wear of spring clips or brackets holding shelves in place. Regular vibration from microwave turntables can weaken pressure points over time. This OEM replacement shelf is compatible with Electrolux, Gibson, Kelvinator and some Kenmore models.5304509642 (AP6230695) replaces 5304478924, 4583734, PS12071384.