"CLIPPER DUET - CLEARLY OUTSTANDING Combined Speed/Distance Log and Echo Sounder in standard 110mm square size. Suitable for cockpit mounting. Depth sounder in feet and Metres. Shallow Alarm and Keel Offset Complete with well proven Transducers. Speed in MPH, Knots and Km/H. Trip and Total Distance in Miles, Nautical Miles and KiloMetres. Speed Limit Alarm"