Available in:Size13mm, 20mm, 25mm, 28mm, 32mm, 33mm & CustomisedRubberButyl, Bromobutyl, Chlorobutyl, Nitrile, Silicon, Latex, Chloroprene, SBR, PBR etc.ColourGrey, Brown, Black, Blue and Various Pharma Code ColoursAlso available Lyophilization (Freeze Drying) & Ready For Sterile (RFS) Rubber Stoppers