Greiner Bio-One polypropylene tubes have excellent optical clarity and strength. Tubes have blue HDPE caps, graduations, and a marking area. Will withstand 3500 RCF x g in a non-supported rotor, 13,000 RCF x g in a supported rotor. Each tube measures 17 mm x 120 mm. RNase free, DNase free, human DNA free, and non-pyrogenic. Sterile.