MERCURY QUICK CHANGE ANODE ALUMINUM COMPLETE WITH ADAPTER USED IN MERCRUISER SIZE: 3/8" THK. X 2 7/32" DIA. WEIGHT: .22 LBS Used with Mercruiser Alpha and Bravo Sterndrives / Outdrive. It takes 2 screws to hold the adapter plate and 1 screw to hold the anode on the adapter plate . Aluminum adapter plate with stainless steel 10/32 threaded insert for long life