This is the Color Cup Screw O-ring for the Model Maker DA500 Paint Gun. It is located inside of the Color Cup and under the Cup Fixing Screw. FEATURES: Rubber construction INCLUDES: One Color Cup Screw O-ring (key #31) REQUIRES: None, item is a stock replacment part. SPECS: Outer diameter: 9mm (.354") Thickness: 2mm (.080") COMMENTS: If the Color Cup Fixing Screw is needed, use HCAR4330. NNA 1/09/05 ir/jxs