This is the Mixture Control Valve O-ring for the #6H and #7D OS Max carbs. FEATURES: Silicone construction. INCLUDES: Two O-rings. SPECS: Outside diameter: 6mm Inside diameter: 3mm Thickness: 1mm COMMENTS: Can be used for other applications where a 3x6mm silicone o-ring is called for.OS EnginesPart OSM24881824