Percs and Bubblers for Lampworking/Glass blowing and making Ash Catchers, Hookahs, and Water Pipes. As shown in pictures, 18mm ground joint, 5" long by 2-1/8" wide midnight blue showerhead bubbler, Pyrex COE33 Borosilicate Glass. For professional/amateur Glass blowers and lampworkers. Each additional piece only Discount!