ST40 Bidata Features include: Sea Talkácompatible for networking to other instruments, multifunction displays and autopilots, high contrastáLCD display for excellent visibility, 3 levels of display backlighting for night use, 28mm tall, 7 segment digits for visibility across the cockpit, 200 Khz frequency, shallow, deep and anchor alarms, depth readout in feet, fathoms or meters, keel or waterline offsets tailor ST40 depth to your boats characteristics, speed readout in knots, kilometers per hour or miles per hour, user resettable trip log, water temperature readout in degrees Celsius or Fahrenheit, master or repeater mode for displaying data at multiple locations.