The millimeter sizes mentioned refer to the dimensions of the glass slides used in the standard product, which does not feature a glass-on-glass design.
You like to keep it simple — that’s why you’ll love the 9mm GRAV® Clear Taster. A clean, minimalist one-hitter made from crystal-clear glass, with a bowl on one end and a mouthpiece on the other. Each 10-pack includes assorted GRAV® logo colors — perfect for quick hits or sharing with friends.