Crimp Seals & Vial Stoppers. Vial Crimpers are available for the following cap sizes – 8mm, 11mm, 13mm, 18mm, 20mm, 28mm, 30mm, 32mm. Other sizes and configurations are available in plain or flip off types. Our vial cap crimper comes in a range of body sizes to suit the crimping head. All sizes can be supplied as either a crimper or a decapper.