Auspex Scientific - The Exciting Science and Educational Store
Twist one of the rubber protrusions off and the solid stopper becomes a one-hole stopper! Twist the second off for a two-hold stopper.
Made of soft, resilient "white" natural rubber, with safe, convenient, countersunk 5 mm holes.
Top Diameter 24 mm
Bottom Diameter 18 mm
Height 25 mm
5 stoppers per pack.