The GTR-IA Tube Rotator packs a lot of value in a simple, easy to use package. With a 'Ferris Wheel' disk design and analog speed control, operation and setup can be completed in minutes the very first time and every time. The fixed angle disk utilizes clips to hold 1.5/2.0mL, 15mL and 50mL tubes. The clips are included with each unit and additional clips are also available for separate purchase.