Borosilicate amber glass with a tapered interior for maximum sample recovery. Specially treated with extra low adsorption (XLA) characteristics to minimize sample interaction with the glass. Includes caps with pre-inserted PTFE/silicone septa. Vials have a wide-mouth opening for ease of filling, especially with automatic pipettors. Use with any GC or LC autosampler with a rack for 1.5/2mL (12 x 32mm) vials. Adjust needle stroke 2-3 mm less than for a flat bottom 1.5 mL vial to prevent damage to the needle.