4 pieces Material Stainless Steel Premium Steel Wire - Made of heavy duty High-Carbon 0.3 MM stainless steel wire, the wire wheel for drill is very strong and durable with a long service life. Outstanding Polishing Effect - Efficiently hack down rust and old paint, making it ready for metal primer after a wipe down. High-density uniform steel wire is tight and durable, leaving a uniform, smooth surface. 1/4" Solid Hex Shank - The handle is easier to grasp and more firm. Not easy to bend and fall off. Include 4 Pcs wire brush wheel cup brush set,3" twist cup brush for large area heavy processing, 3" copper-plated wire cup brush for gentle grinding over large area, 1" knot pen brush for precise and thorough cleaning in hard-to-reach corners, and the 11" copper-plated pen brush for delicate sanding in hard-to-reach corners to remove residual stain. Wide Application - Easily and smoothly remove heavy corrosion, rust, paint, spatter and scale. The drill wire brush attachment are ideal for polishing weld edges, debur metal and wood.