General description Brand new and high-quality miniature deep groove steel ball bearings, designed for smooth operation and durability. These bearings are impregnated with grease for optimal performance. Technical specifications Material: Steel Outer diameter: 22 mm Inner diameter: 8 mm Thickness: 7 mm Quantity: 40 pieces per pack Measurement allowed error: +/- 1-3 cm Other information Note: Light shooting and different displays may cause the color of the item to differ slightly from the actual product.