The RD30 shows you precise depth to 2 feet and temperature to 0.02 of a degree. Simply connect the RD30 to the Furuno Smart Sensor and you are ready to go. The Smart Sensor depth sensor is entirely encased within its own housing and connects directly to the RD30 display via the NMEA data port-no additional processor or junction box needed. The Smart Sensor operates at 235kHz, a frequency chosen for its ability to perform at high speeds and in very shallow depths. Furuno, (360) 834-9300; www.furunousa.com.