AquaCraft propeller is constructed of high quality Copper-Beryllium-Titanium material that is rigid but not brittle and can be sanded and shaped with less effort than stainless steel props. Copper-Beryllium-Titanium material stays sharper longer and is less prone to dulling and chipping. True center bore hub with raised letters and numbering for easy. identification. Tumbled to remove any excess cast flashing.