Polypropylene (PP) conical bottom tubes, dual graduation scale to avoid parallax error due to viewing angle, and large screen-printed writing area. White screw cap in polyethylene (HDPE) guaranteed to be airtight at -95kPa. Free of metals with an ICP-MS detection limit of less than one part per million (PPM). DNase & RNase free, non-cytotoxic, biologically inert. Ø 30 x 115 mm - RCF max= 20,000 g. Autoclavable at +121°C and freezable up to -80°C.