Features 1、These miniature bearings are made of high quality bearing steel for low noise and long service life. 2、They are double shielded to avoid contaminants entering and save lubricant. 3、Bearings have 4mm inner diameter, 13mm outer diameter and 5mm thickness. 4、These are great for small hobby 4mm shaft/rod projects. 5、There comes total 10 pieces miniature bearings which you may use for many different projects. Specification Features: These miniature bearings are made of high quality bearing steel for low noise and long service life. They are double shielded to avoid contaminants entering and save lubricant. Bearings have 4mm inner diameter, 13mm outer diameter and 5mm thickness. These are great for small hobby 4mm shaft/rod projects. There comes total 10 pieces miniature bearings which you may use for many different projects. Specification: Model: F624ZZ Inner Diameter: 4mm / 0.16in Outer Diameter: 13mm / 0.5in Thickness: 5mm / 0.2in Property: High speed Application: Universal Rolling Element: Single row balls Race Type: Deep groove race Material: Bearing steel Angle: 15 degree Sealing: Double-shielded Weight: 33g / 1.2oz (approx.) Package list: 10 * Bearings Package List