Airmar DT800 P17 Smart Sensor 235kHz NMEA 0183Depth and temperature 235 kHz frequency prevents mutual interference with other echosounders on the vessel Depth performance from 500 mm (1. 6') to 183 m (600') NMEA 0183 version Cable lengths up to 100 m (330') are possible with no loss of performance Plastic bronze or stainless steel housings available Retractable insert in plastic bronze or stainless steel housing with a water valve Available in low profile countersunk or beveled edge housings