BenchMixer Vortex Mixer, COMBO Head, Cat. No.: BM-BV1000-COMBO, Powerful motor for INSTANT vortexing, Continuous or “touch” operation, Q-Drive™ dynamic balancing system, Variable speed from 200 to 3200 rpm, Wide variety of accessories. The BenchMixer™ sets the new standard in vortex mixing. With advanced Q-Drive™ technology, the BenchMixer provides smooth instant vortexing of even the largest sample sizes, including full 50ml tubes. The unique counter-balance system creates maximum vortexing action, while minimizing noise and excessive vibration. This results in quieter, more efficient and longer lasting operation.Other features include: “no-walk” suction feet, cold room/incubator compatibility and spill-proof electronic controls.