Sierra 18-99529 Volvo Penta DuoProp Outdrive Gear Lube Fill AdapterDesigned for Volvo Penta and OMC joint venture duoprop drive units, allowing connection to standard 3/8"-16 lube pump fittings. It includes an O-ring for a secure fit and replaces part numbers 551-334v and CDI-551-334v.Key Features Fits Volvo Penta and OMC duoprop drive units; Adapts to 3/8"-16 standard lube pump fittings; Includes O-ring; Replaces 551-334v, CDI-551-334v;