Blue, 12 x 32 mm Screw Neck Cap and Preslit PTFE/Silicone Septum, 100/pk. As a part of Aijiren Technology’ wide selection of vials, caps, and other sample accessories, this blue polyethylene screw cap is compatible with a range of vials and other products. Screw caps are designed in consideration with other vial parts in order to achieve high-performance