Sierra's 18-7234 Flame Arrestor is designed for use with Mercruiser 4 and 6 Cylinder stern drives. It features a 7.000" outside diameter and a 2.280" height. It does not have any vent tubes. Includes one flame arrestor per package. It is interchangeable with Mallory 9-31101 and Mercruiser Stern Drive 805016A1. Each Sierra product meets or exceeds the original equipment part it replaces.