Iodine flask with size 22 stopper Size 22 PTFE standard taper stopper is included A durable matte-finish ceramic enamel marking spot takes writing and erases easily Designed from ASTM Specification E1404, Type II, Class 3 requirements

Reinforced bead at top 300 mL and larger sizes have tooled necks 10 and 30 mL sizes are designed from ASTM Specification E 147; 100 mL through 800 mL sizes are designed from ASTM Specification E 1377, Type 1 requirements.