The Zimar AS-50 prop nut zinc is hand-poured using special high-grade zinc ingots that are 99.995% pure zinc to ensure the highest-quality cathodic protection. All Zimar anodes are made in the USA and meet the Mil-Spec A-18001K, Mil-Spec A-18001A, and Mil-Spec A-18001. For Azimut yachts with 50mm diameter propeller shafts, which includes models AZ40, AZ42, AZ43, AZ46, AZ50, AZ55, AZ58, AZ68, and others. Note: Confirm the diameter of your propeller shaft as some of the above Azimut models have 60mm propeller shafts, not 50mm. Fits over hex nut measuring 46mm across the flats. M10 x 35mm mounting screw NOT included, 8mm hex wrench required to install. Weight 2.7 lbs. Height: 3-1/4” Diameter 2-7/8”