These popular conical-bottom centrifuge tubes are made of ultra-clear polypropylene copolymer.They feature printed graduations and smooth inner walls for easy filling and sample preparation. ● Material:PP ● Color:Clear ● The outer surface of the tubular body is smooth,uniform color ● Clear graduate printed on the outer surface,white areas can be written text,chloroform-resistant ● Autoclavable at 121℃(249.8℉),Freezable to -45℃ (-104.4℉) ● Flat cap surface for writing,and pass rigorously leak test ● Gamma ray sterilization or Unsterilization Optional