Larger opening provides increased target area for needle penetration. Closures are ideal for autosamplers requiring closure to support or hang vial in tray (such as Hitachi, Jasco, Shimadzu etc.) Available in a wide assortment of colors. The Top Seal™ closure with a 0.010" molded septa allows for easy needle penetration and is inert to most solvents. The one piece design saves time by eliminating the process of assembling liners in the closures.