Screw cap are available in 8-425 screw cap, 9mm screw cap, 10-425 cap, 13-425 cap and 24-400 cap. 8-425 screw cap for HPLC vial Our screw-top 2ml HPLC vials and screw caps are the perfect fit for HPLC and GC instrument platforms across a wide variety of applications, including pharmaceutical, environmental, energy and fuels, forensics