The KOBOLD DON Series oval gear positive-displacement flowmeters are the preferred choice for measuring clean, high and low viscosity liquids such as lubricating/hydraulic oils, diesel fuels, chemicals, solvents, resins and pastes. This flowmeter uses 2 precision-machined oval gears which allow for a very specific volume of liquid to pass through the meter with each rotation. These gears enable the DON flowmeters to precisely measure liquid flow over a very wide viscosity range.