Features 1、These bearings are made of high quality steel for low noise and long service life. 2、They are rubber sealed to avoid contaminants entering and save lubricant. 3、Bearings have a 5mm inner diameter, a 16mm outer diameter, and a 5mm thickness. 4、These are great for small hobby 5mm shaft/rod projects. 5、There comes total 20 pieces miniature bearings which you may use for many different projects. Specification Features: These bearings are made of high quality steel for low noise and long service life. They are rubber sealed to avoid contaminants entering and save lubricant. Bearings have a 5mm inner diameter, a 16mm outer diameter, and a 5mm thickness. These are great for small hobby 5mm shaft/rod projects. There comes total 20 pieces miniature bearings which you may use for many different projects. Specification: Model: 625RS Material: Bearing steel Type: Deep-groove high-speed Rolling Element: Single row Inner Diameter: 5mm / 0.2in Outer Diameter: 16mm / 0.6in Thickness: 5mm / 0.2in Quantity: 20pcs Weight: 105g / 3.7oz(approx.) Package list: 20 * Bearings Package List