Metal 3-Piece Grinder with Black-light Designs - 12 PackEquip your collection with the Metal 3 piece Grinder with Black Light Designs display. The display comes with 12 units, and each have a different black light reactive design on the lid. The lid is secured with a magnetic closure and underneath is a shredding chamber with sharp teeth. This is a 3 piece grinder, so you'll also have a pollen collecting chamber and screen. It measures 2 inches in diameter.