Reliable material: these tray rotating support rings are made of high quality material, temperature and decay resistance, safe and reliable to use, and have a -span Package Contents: enough quantity to use and replace, also it is a good choice to share them with your families and neighbors About size details: the outer diameter of microwave roller ring is . 8.7 inch/ 22 cm, the inner diameter of it is . 8.1 inch/ 20.5 cm, the wheel of edge is . 0.59 cm/ 1.5 cm in diameter, proper size for supporting glass tray Widely compatible: the microwave turntable rotating support ring is suitable for serving as turntable bracket base, widely compatible with most microwaves, good replacement for your broken tray rotating support rings