This is original equipment from Arizer, and it promotes exceptional functionality. There are several advantages offered by a straight tube mouthpiece or curved or bent tubes. For instance, it is easier to store a straight glass stem within a vaporizer case. It can also be conveniently slid inside your pocket. The straight shape also keeps residue to build up inside the tube and allows for easy cleaning. Each product includes 1 piece of straight glass stem measuring about 4.3 inches.