This is the stock 5.5mm Carb Reducer that comes on the following Carbs: OSMG2473 11H OSMG2474 11H(B) FEATURES: Genuine O.S. replacement parts Black plastic construction INCLUDES: One 5.5mm carb reducer Two O-rings OSMG6220 REQUIRES: Installing included O-rings on reducer then sliding into carb SPECS: Height: 0.57" (14.4mm) Diameter: 0.22" (5.5mm) (approx) ID @ bottom 0.39" (10mm) (approx) ID @ top 0.49" (12.5mm) OD main body 0.63" (16mm) knurled flange at top OS EnginesPart OSM71533055