Abstract: Provided is an automated paperless order selection system of the type wherein an electronic order picking unit moves horizontally along a rail directly to a product storage location, thereby decreasing the distance traveled by the order picker and improving the accuracy of the order picking process, such order picking unit having an incremental encoder means for determining its exact location on the rail, and having a wireless radio frequency data communication (RF/DC) capability, and preferably including a printer, bar code scanner as well as audit and inventory report features.