Park Tool CB-4 is a 100% biodegradable, natural, plant-based degreaser formulated for use in the CM-5.3 Cyclone Chain Scrubber, CM-25 Professional Chain Scrubber, or with a scrubbing brush as a general purpose degreaser. When used with a chain cleaner, CB-4 gets bicycle chains clean inside and out so they&';re good as new. Will not harm alloy, plastic, rubber, or carbon fiber parts, so it&';s safe to use for cleaning cassettes, chainrings, pulleys, or any other component that accumulates muck and grime. CB-4 FEATURES - 16 oz. (474 mL) bottle