Mercury - E-Ring for Alpha One Gen II Gearcase Retention Component Hardened Marine Alloy 8M0214951. Overview. When you spend your weekends on the water, you come to appreciate the small parts that never make a fuss but hold everything together. An E-Ring might not be the first thing you think about when you look over your boat, but when it fits right and stays put, you can feel the difference in the way your drive behaves. There's a quiet confidence that comes from knowing each component is secu