For use with fixed-angle rotors 05-406-13 and 05-406-14 and swinging bucket rotor 05-406-41 (for Model 5417R), and fixed-angle rotors 05-400-122 and 13-688-198 (for Models 5415D/5415R) Adapters fit any Eppendorf™ rotor with slots to hold 1.5 to 2.0 microcentrifuge tubes with maximum 11mm O.D