This is a lightly used Fish Hawk 840, It is in supershape and works great. Once you use this 840 you will wonder how you ever did without it. This will give you speed and temperature readings both at downrigger and surface. The probe sends a wireless sonar signal to your transducer mounted on boat(No wires to mess with on the downrigger cables). The probe runs on a 9 volt standard battery(not included). These units run about $650.00 new
I am asking $370.00 for this like new Fish Hawk 840. You may cal me at 616 293-3856