PerkinElmer. PTFE/Silicone Pre-slit Septa together in an environmentally clean, re-sealable clamshell pack. Volume: 2 mL Size: 12 x 32 mm I.D.: 10 mm Finish: Screw Top with Closure Kit Description:Clear glass vial PTFE/Silicone Pre-slit Septa with Black Cap This cap and septa is also available 500/pack.