This anode fits sail drive units SD-20, SD-30, SD-31, SD-40, and SD-50.

The stainless steel adapter kit is required when you change from a solid to a split ring anode.
Each adapter kit includes 4 (M-6) Allen flat head machine screws and 2 (M-8)

Split-ring sail drive
Galvanized steel mounting core
122 mm center to center; screw size is 8 mm
Conforms to Mil Spec MIL-A-18001 for maximum protection
Made in California, USA