Amber Vials for Chromatography, includes 100/PK of 2ml RSA glass vials with a 9mm screw thread.Caps sold separately. These Reduced Surface Activity (RSA ) glass autosampler vials are designed and manufactured with a pristine interior surface that is not coated or treated in any way but lacks the typical silanol sites (hydroxide groups) other vials, even "Certified Vials" will have.