Natural rubber stopper with sleeve extension that fits over the lip of the glass item which provides a septum top which can be punctured with a needle.

Natural rubber stopper with sleeve extension white that fits over the lip of the glass item which provides a septum top which can be punctured with a needle.

PTFE sleeves are inserted between standard ground joints to eliminate the use of grease and prevent sticking. Wall thickness is approximately 0.05 mm.

PTFE sleeves with a substantial shoulder for ease of handling are inserted between standard ground joints to eliminate the use of grease and prevent sticking. Wall thickness is approximately 0.05 mm.