Bark Cork Stopper, Size 13

This pack of 10 bark cork stoppers is size No. 13, measuring 24mm at the bottom, 30mm at the top, and 31mm in length. The tapered profile provides a secure friction fit in flask necks and test tubes with matching bore diameters. Natural bark cork is compressible, chemically inert to most common laboratory reagents, and easy to bore for inserting glass tubing or thermometers. These stoppers are suitable for general-purpose sealing of flasks, bottles, and tubes in educational and laboratory settings.