Garmin GPSMAP 421s 4-Inch Waterproof Marine GPS and Chartplotter (Without Transducer) Garmin GPSMAP 421S GPS Chartplotter/Fishfinder Combo w/o Transducer Garmin GPSMAP 421S GPS CHART Fishfinder COMBO W/O XDUCER Brand New. Frequency = NONE | Internal/External Antenna = Internal | Resolution (VxH) = 240 x 320 | Screen Size = 4.0/3.2 x 2.4 | Screen Type = Color | Speed/Temp = NONE | Touchscreen = No | Transducer Type = Not Included | Waterproof Rating = Waterproof | Watts RMS