... polypropylene (PP) molded/printed graduations or ungraduated with silicon ring ISO9001 1ml,2ml freezing tube1, material: PP;2, ... available;3,all of them are with silicon "O" ring;4,different colors and volums available Item Code Description ... Size PackingSHB01Freeze tube,silicon ring,ungraduated 1ml 500pcs/bag,24bags/cartonSHB02Freeze tube,silicon ring,ungraduated 1ml 500pcs/bag, ...