688 miniature deep groove ball bearing

A 688 miniature deep groove ball bearing is a small mechanical bearing designed to reduce friction and support smooth rotational movement between moving parts. It typically has an 8 mm inner diameter, 16 mm outer diameter, and 5 mm width, making it suitable for compact mechanical assemblies. It is commonly used in 3D printers, small robots, wheels, gears, pulleys, model machines, and other STEAM projects.