Mercury - Quicksilver 821629Q1 Aluminum Drive Shaft Housing Anode MerCruiser Alpha One Gen II Sterndrive 821629Q1. Overview. Protect your drive before corrosion gets a chance to start. The Quicksilver 821629Q1 Aluminum Drive Shaft Housing Anode is designed specifically for MerCruiser Alpha One Gen II sterndrives, helping shield your drive and engine from the damage caused by galvanic corrosion.. Cast from high-quality aluminum, this anode performs in both fresh and saltwater, wearing away gradua