Simply rub your mitt or brush across the Grit Guard Insert while washing your vehicle, boat, motorcycle, or RV. Radial surface design extracts particles and contaminants from mitts and brushes. Gravity causes dirt to settle to the bottom of the container. Wash water stays clean - scratch-free clean. Four quadrants on the base calm the wash water. Insert works great for: small parts cleaning, wet sanding, oil filter draining...and much more! 10 1/8” diameter , 2 1/2” high weight 6 oz. Solvent resistant.