Rubber Stopper One-Hole size 5 1/2

Rubber Stopper One-Hole size 5 1/2 Bottom Diameter 24 mm Top Diameter 28 mm Lentgh 25 mm 

These black high-percentage rubber stoppers are low in free sulfur and have a single hole to facilitate laboratory procedures.

Remain resilient and pliable under most laboratory conditions

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.