The grinding head is made of nylon fiber, abrasive grains and special adhesive. 6mm round fits most drills and grinders. Good heat dissipation, avoiding to the workpiece during processing. Mainly used for polishing, deburring, cleaning, derusting and surface texture treatment of various materials such as metal, wood and plastic. Colour:As Shown Material:nylon fiber Size:5 x 5 x 2.5cm Grinding head Size: 30mm 40mm 50mm Package Contents: 30 x Nylon wheel polishing head with handle 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.