This top quality line of centrifuge tubes feature flat-top, plug-seal leak resistant screw caps, a large white writing area and printed graduation marks. Sterile tubes are RNase free, DNase free and Pyrogen free. Polystyrene (PS)Cap is made from High Density Polyethylene (HDPE)Dimensions: 29.5 x 114mmSterile tubes are RNase/DNase and Pyrogen FreeSpin Rate: 1700 RCF (3000 x g)White graduation marks and large white writing area