Vostermans Varifan Variable Speed Drive with Manual OverrideAvailable in three different models that have a 0 10 V or 4 20 mA input signal. Easy to access toggle switch to select manual or automatic mode as well as a manual speed selector dial on the faceplate. Internal minimum speed adjustment with possibility to work continuously at minimum speed. Comes in a rugged, sealed enclosure that protects from light, moisture and dust. Includes extended supply voltage range and a radio interference filter.