Using pure polystyrene(ps) raw materials in line with USP-Class VI standard, GMP 100,000 clean workshop production. 2 types of lids, sealed lids and vented lids. There is a frosted writing area on the side of the culture bottle neck and a volume scale on the side for easy identifification. Stackable design, easy to stack, not easy to slip. No pyrogen, no endotoxin, no cytotoxicity Irradiation Sterilization, SAL 10-6