The Bent Glass Stem is compatible for use with the Arizer Air, Arizer Air 2, Arizer Solo and Arizer Solo 2. From tip to tip, the stem measures 12.5 cm (the bend is about 5 cm). This fits perfectly with the vaporizer it’s designed for. There might be some differences in the diameter when you use it for other brands which may result in a looser or tighter fit when you insert it into the upper heating chamber. Some users prefer the Bent Glass Stem because the resin is trapped right at the curve, which they think is a little healthier.