Human Grade Grinder 4R (2.5")The Human Grade 2. 5" (63mm) 4 Piece Grinder with a rubberized coating offers a secure, comfortable grip and a sleek modern finish. Designed for smooth, efficient grinding, it features precision teeth, a pollen catcher, and durable construction built to last. Retail Unit: One (1) Grinder Pieces: 4 (Four) An upper chamber, grinding chamber, pollen screen, and a bottom chamber for collecting the finer particles Size: 2. 5" (63mm) It's the perfect size