4 piece kit fits all drills and impact drivers. 1/4 inch quick change hex molded-in shaft. The Red brush has stiff bristles for heavy duty scrubbing of flooring, concrete, and brick. The Green and Yellow brush have medium stiffness bristles for all purpose scrubbing of Tile and Grout, Bathroom surfaces, and stairs. The white drill brush attachment has soft bristles for cleaning Glass, Leather, or upholstery. Drill NOT included. Drill Powered four piece Scrub Brush Kit