3.0" Inch Dia Machined in Florida from 6061 Medical Grade Aluminium. Has 2 rare earth magnets. This grinder has been designed, and optimized to produce a very fine grind for vaporizers. Some considered this a finishing grinder. The more you pack into the bowl the finer it will grind. The grinder has been designed for 8" arm bands so customizing is easy and fun. The rubber grips also help with traction when grinding full loads. We have decided to keep this grinder natural so there's no annodize or engraving. To keep it running smooth It is suggested to use hot dish soap and a firm brissle brush for frequent cleannings. Adding to the dishwasher will discolor the grinder.