Master Edition metal detector features three operation modes, large control knobs to adjust ground balance, volume, discrimination between metals, tuning which fine-tunes the balance between the detector"s receiver and transmitter, sensitivity and volume control for speaker or headphones (headphones not included), and a low battery indicator. Operates on two 9V alkaline batteries (not included). 8” waterproof search coil allowing you to search in shallow water. Detection results are displayed on the analog meter and pointer. 1 Year limited warranty