The Beckman Coulter Microfuge 18 Centrifuge Rotor Adapter is designed to adapt 0.2ml, 0.4ml, and 0.5ml microcentrifuge tubes to fit in the Microfuge 18 Centrifuge rotor. It allows the centrifuge to spin smaller volume tubes up to 18,000 x g. The adapter is made of durable polypropylene and can hold up to 6 microcentrifuge tubes. It has a low profile design to provide a stable fit in the rotor. The adapter should only be used in the Microfuge 18 Centrifuge.