Closes with a “snap” and stays closed during centrifugation Frosted cap surface for labeling Frosted panel on the side for writing 0.28mm piercing port in the center of the cap allows easy access to sample by syringe needle Autoclavable Available as MAXYclear for excellent visibility and in a variety of other colors Co-polymer tubes offer exceptional strength and chemical resistance Homopolymer tubes are more resistant to autoclaving 0.6,1.5 and 2.0mL microtubes are certified boil proof Max. RCF: 14,000 x g (0.6mL); 20,000 x g (other sizes)