A vial (also phial) is a relatively small glass vessel or bottle, used to carry liquids, usually injectable medicine. The use of vials is widespread with anabolic steroids and many brands are using them. The glass can be colourless or coloured, clear or amber. There are different types of closure systems, e.g. Screw vials (closed with screw cap or dropper/pipette), Lip vials (closed with cork or plastic stopper), Crimp vials (closed with a rubber stopper and a metal cap). A vial can have a tubular shape or a bottle-like shape with a neck. The bottom is usually flat unlike test tubes which have usually a rounded bottom. Modern vials can be made of plastic (e.g. polypropylene). These can have other closure systems like a flip-top/snap cap.