in 11mm size provide a secure seal that minimize evaporation, even with volatile samples. Snap caps are often more convenient than crimp caps they can easily be applied and remove by hand. An audible click ensures a secure seal has been formed and that the cap is correctly aligned.Both snap and crimp vials can be closed with either snap caps or crimp caps. Clear and amber vials with or without graduated writing area in available. Both pre-slit and non pre-slit caps are in supplied.All of Starlab vials are excellent fitted for autosamplers.