These black, high percentage rubber stoppers are low in free sulfur and have a single hole to facilitate laboratory procedures. Stoppers sized as 000 through 0 have a 3mm diameter hole; the size 1 stopper has a 4mm hole. Stoppers sized as 2 and larger have a 5mm diameter hole. Remain resilient and pliable under most laboratory conditions.

Length: 21mm

Top Diameter: 13mm

Bottom Diameter: 8mm