Eisco Labs #0 Cork Stoppers, pack of 10, are tapered natural-bark stoppers ideal for sealing bottles, flasks, and test tubes with mouth openings 8–9mm in diameter. Each cork measures 13mm in length, with a 7mm bottom diameter and 10mm top diameter. The natural cork construction is durable and will not crumble or break easily under normal use. Designed for professional laboratories but equally well suited to classroom, home, and garage applications — use for homebrewing, sealing wine and beer bottles, spice rack vials, fishing, DIY corkboards, and creative projects.