Screw thread caps and vials are often used in conjunction with Shimadzu, Spectra-Physics, Varian, and other autosamplers Vials are manufactured of Clear, Type 1 Class A or Amber, Type 1 Class B borosilicate glass and include a write-on patch for sample identification Caps are made of high quality polyproylene to exact manufacturing tolerances and lined in a controlled manufacturing environment Our septa use only the highest quality materials to ensure proper function and can be pre-slit to ease needle penetration Designed for multiple injections and/or longer sample cycles - for both GC and LC applications High quality silicone compounds are used to ensure proper re-sealing and reduced chances of coring.