Black Phenolic Caps with 14B white rubber liners are autoclavable. The Liner is compliant with FDA 21 CFR 177.2600 Rubber Articles Intended for Repeated Use. The liner exhibit good resiliency and resistance to moisture vapor. The closures provide consistent adherence to close dimensional tolerance. Phenolic Caps known for providing the widest range of chemical compatibility and for being the most temperature tolerant of plastic closures. They also provide the most consistent adherence to close dimensional tolerances. Ideal for pharmaceutical applications.