KIMBLE® KONTES® Vigreux Distillation Column manufactured by DWK Life Science is made from 33 expansion, low extractable borosilicate glass conforming to USP Type I and ASTM E438, Type I, Class A requirements. It comes with a Standard Taper outer joint at the top and a Standard Taper inner joint at the bottom. The indentations over the entire length improves vapor-liquid contact.