@sukili137: High Quality Materials—Imported medical grade polyethylene (PP) Highly Compatible—Conical design, compatible with different brands of centrifuges High Centrifuge Force—Thick conical bottom increases the maximum centrifugal limit Low Absorption—Less residual liquid, less wall-hanging effect Double Threaded Design—Enhanced sealing, easy to operate with one hand High Transparency—Clear and transparent tubes for easy observation of samples and accurate reading of data Sterile And Pollution-free—DNase/RNase free, pyrogen free, PCR inhibitors free