Brass High Carbon Crimped Steel Wire, Thick bristles, For use with electric drills, Ideal to remove rust, paint residue and polish metal objects. Diameter: 2-3/4" (69.8mm), Thickness: 19/32” (15mm), Wire Thickness: 0.30mm, Shaft Size: ¼” (6.3mm), Wire Length: 18.5mm, Maximum Speed: 4,500rpm