Innovative Products of America's XL Bore Brushes come in 25mm, 30mm, 35mm and 40mm diameter brass or stainless steel. Available individually or in a 4-piece sets, these brushes are 3.5" in length with a 1/4" drive shank. Attach these brushes to a 1/4” driver or low-speed gun to remove debris from throttle bodies, brake calipers, engine components and much more.