| Inner Diameter | 3 mm |
| Outer Diameter | 7 mm |
| Thickness | 3 mm |
| Model | W638/3-2RS1, W638/3-2Z, W639/3-2RS1 |
| Lubrication | Grease or Oil |
| Origin | China |
High-precision miniature deep groove ball bearings with rich stock, 100% on-time delivery, and OEM/ODM support. Suitable for compact, high-speed applications requiring low vibration (Z1V1–Z3V3) and reliable grease/oil lubrication.