This Ohaus fixed-angle rotor, part number 30314831, takes 6 x 50 mL tubes. The part is catalogued under the Ohaus Frontier 5000 rotor series. Maximum speed and relative centrifugal field depend on the centrifuge this rotor is installed in. No manufacturer datasheet came with this listing, so verify the rating against Ohaus documentation for your machine. Ohaus 30314825 shares this capacity and tube format under a different part designation, so check the full part number when ordering.