Usage Tips:providing a comprehensive solution for your polishing and buffing needs Size Information: Our buffing wheels for grinders have a diameter of approximately 8 inches, with a center hole diameter of about 5/8 inches. They consist of 12 layers to better polishing effectiveness. Each aluminum polishing compound bar weighs 70 g / 2.5 ounces Quality Material: These cutting buffing wheels are made from cloth of different densities: 1 blue airway buffing wheel (12 ply) for hard polishing, 1 orange airway buffing wheel (12 ply) for coarse polishing, 1 yellow airway buffing wheel (12 ply) for medium polishing, and 1 white airway buffing wheel (12 ply) for fine polishing. The wheels are designed for different purposes, and the center ring ensures durability for long-term use, providing longer and cooler operation compared to standard buffs. Recommended maximum RPM safety limit is 3000 Simple To Use: These buffing compound bars work with buffing polishing wheels. Simply turn a buffing wheel on a grinder, motor, or drill, and lightly the compound against the wheel. Heat and friction transfer the compound onto the polishing wheel Wide Application: The airway polishing wheels and polishing compound bars are suitable for polishing vehicle parts such as fuel tanks, wheels, and bumpers, as well as metal finishes and other accessories made of aluminum, brass, copper, and stainless steel Color: As shown Material: Metal+Cloth Package Contents: 4 pieces * 8-inch airway polishing wheels 5 * different functional colors of polishing bars Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.