The X4 Probe uses a sonar signal to send water temperature, and trolling speed information at the downrigger ball to the boat.
- Detects speed changes of 1/10 MPH
- Probe uses a 70kHz sonar signal to send data
- Water-activated probe extends battery life
- Powered by four AA batteries
- Includes swivels to attach downrigger weight
- Epoxy potted electronics with double O-ring battery cap
- Compatible with legacy Model 840