This high-quality center socket is a must-have for boating enthusiasts. Designed to fit Mallory 9-72403, MerCruiser 39383, 393831, and 39383T OMC, this Sierra 18-2128 part is perfect for your boat's transmission and components. With its durable construction and reliable performance, you can trust that your boat will run smoothly and efficiently on your next adventure. Don't settle for anything less than the best - choose Sierra for all your boating needs.