11mm aluminum crimp top seals have a larger opening to ensure proper needle penetration. 2ml, 12*32mm 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 aluminum. 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 absence of pigments eliminates additional sources of contamination. 005atchinalabsup features: volume/capacity:? 2.0ml (normal volume) feature: 12*32mm vials, 11*1mm ptfe/silicone septa, 11mm aluminum crimp cap qty/pack: 100/pack model:? 11mm wide opening crimp-top vials