Labline Orbit Shakers are made of high quality components and precision engineering and are well designed to provide a uniform, balanced shaking motion. The 3520 model is compact and can be easily moved from the lab bench to any location where it is needed. Shaker speed ranges from 40 to 400 RPMs and the solid state speed control provides accurate regulation of the speed. The drive mechanism produces a ¾” inch diameter circular motion and is counterbalanced to ensure smooth, vibration free operation at any speed. The shaker platform rotates on nine permanently lubricated, sealed ball bearings. The entire drive, housed in a precision machined, cast iron base, sits on four cushioned feet which prevent creeping. This unit is in very good condition  and will give many years of durable service.