Screw closure has internal thread. Vial has external thread. Deep-skirted closure allows single-handed aseptic technique without contaminating vial contents. Large diameter vial opening allows easy filling. Self-standing. Similar leakproof design to the linerless closures used for Nalgene bottles — sealing ring in conjunction with specially designed threads. White marking area, fill line and graduations are printed on the side. Preassembled and radiation-sterilized. Non-pyrogenic and non-cytotoxic.
Warning: No screw-cap vials, including Nalgene cryogenic vials, should be immersed in liquid nitrogen as liquefied gas may be entrapped inside the vial and lead to pressure build-up.