Crimp seals, 11 mm, with PTFE/rubber septa are for use with 20 mm crimp top vials. The PTFE/rubber septa are compatible with most organic solvents many organic solvents: acetic acid (<50 %), acetonitrile, acetone, alcohols, dmso, phenol and are not compatible with alkanes, benzene, carbon disulfide, chlorinated solvents and cyclohexane.<>