The Touch Vortexer mixes test tubes contents thoroughly and quickly with a vortexing action that swirls the liquid. RPM is 400 to 2500. The unit may be set to run continuously or to activate when any tube up to one inch is touched to the cup. Designed with a permanent-magnet, filtered DC motor, the Touch Vortexer will run cooler with less motor stress. The variable-speed motor produces constant power and is less susceptible to overloading when excess pressure is applied. The Touch Vortexer is on of the most durable, user-friendly small vortexers available today. Size: 6"w x 7"d x 5"h. Shipping weight: 9 Lbs.