Thick wall protects inside media and solution, and the screw cap ensures bottle leak-proof Product Feature * USP Class VI Polyethylene Terephthalate * 125ml,250ml,500 ml and1000ml * Lig htweight, shatter proof, hightransparent * Low permeability to carbon dioxide andoxygen * Gamma Sterilized * DNase-free, RNase-free, Non-pryogenic