Highest Quality Aircraft Grade Aluminum Four Piece Herb, Spice or Tobacco Pollen Grinder (Black) Magnetic closure. 2 1/4 Heavy duty and durable aircraft grade Aluminum construction 14 teeth in top section and 12 teeth in bottom section for extra fine grinding Durable ring included designed to for an easy and fast grinding experience 4 piece, 3 chamber design - Mesh screen for fine pollen filtering