Wheaton® MicroLiter Assembled Kit Clear Vial with Marking Patch, Green Cap and PTFE/Silicone Septa. Wheaton® MicroLiter Screw Thread Autosampler Vials come in fully assembled kits that are clean, sealed and ready to use. Assembled kits are shipped with the septa installed inside the cap and the cap screwed onto the vial. MicroLiter vials are manufactured from Type 1 borosilicate glass. Vial