This is the replacement Complete Carburetor for the / O.S. 91HZ engine - OSMG1975. / / FEATURES: Aluminum construction / Replaces worn or damaged carburettors / / INCLUDES: One assembled carburetor / One carb O-ring gasket / / REQUIRES: Installation / / SPECS: Diameter: .59" (15mm) outside diameter of mounting neck / Diameter: .47" (12mm) inside diameter of mounting neck / Height: 1.64" (42mm) / Width: 3.74" (95mm)