Yes, this is the famous MarkFish which lets you make waypoints on your GPS from your Fish finder or from an external button.
The unit comes with wiring instructions, a set of 8 x Heatshrink glueline crimp connectors, and a 1 Amp standard blade fuse.
Markfish enclosure is fully sealed against liquid ingress, and has integrated mounting holes
Marine grade wiring
Operating Voltage: 9 to15Vdc
Power consumption: Approx 100mA
Serial Input: Connects to NMEA 0183 OUT from Fish Finder
Serial Output: Connects to NMEA 0183 IN of GPS
Serial Data: 4800 Bits per second, 8 Bit word, No parity, 1 Stop bit.
External waypoint trigger: Waypoint is sent to GPS when this wire is earthed using a suitable push button. (Button is not included)
Dimensions: (Approx ) W: 8cm x H: 4cm x D: 2.5cm
Weight: (Approx) 200 gram