* Made from medical grade USP VI 100% pure polypropylene, available in 7 different cap colors.
* Temperature resistance -80C to 120C, suitable for ultra-low temperature refrigerators (not for storage in liquid nitrogen vapor phase).
* Thickened walls, cap with built in O-ring gasket to prevent leakage.
* Spiral cap and wall are made of polypropylene with the same expansion coefficient, further increasing the seal at different temperatures.
* Electron beam irradiation sterilization.
* DNA, RNA, pyrogen and endotoxin-free.
* Sterilization optional.