Clear glass or polypropylene inserts for 8mm HPLC and GC autosampler vials are available in a variety of configurations with usable volumes from 125μL to 200μL. 6 Fisherbrand™ 15mm PP Screw Seal, Black, Closed top, 15-425 thread, Assembled septum Polypropylene caps are chemically inert and suitable for most chromatography applications.