screw headspace caps, septa, and vials are designed especially for use with agilent's and otherrotating or robotic arm samplers . headspace vials are manufactured of clear, type 1 class a or amber, type 1 class b borosilicate glass . caps are made of magnetic precision metal to exact manufacturing tolerances and lined in a controlled manufacturing environment . our septa only use the highest quality materials to ensure proper function and can be pre-slit to ease needle penetration. designed for single injection and/or short sample cycles, particularly for lc applications absence of elastomer layer reduces potential for contamination. features: volume/capacity:? 10ml, 20ml (normal volume) feature: 22.5*46mm, 22.5*75.5mm vials, 17.5*1.5mm ptfe/silicone septa, 17mm screw-thread metal cap qty/pack: 100/pack model:? precision screw- thread headspace vials