If any parts are missing or broken, please call Harbor Freight Tools at the number shown on the cover of this manual as soon as possible. Operating Instructions Read the entire Important Safety Information section at the beginning of this manual including all text under subheadings therein before set up or use of this product. Remove the back cover on the Display and, observing polarity, insert 4 AAA 1.5V batteries into the unit. Close back cover. Plug the Transducer (29) into the top of the Dis