2ml clear borosilicate glass screw top vial, no markings, with septa . The associated 9 mm screw caps and closures come with septa lids with a red silicone, white PTFE insert in a blue short screw thread polypropylene cap. Our 4ml Screw Thread Vials & Caps - Greenwood Products. 4mL Clear screw thread vial graduated with Numbers ( Vial # C4015-11W) w/ black open top red PTFE/White Silicone septa (Cap # C4015-75) Assembled to vial. Sample Vials and Accessories - Waters Corporation