This Wireless Sensor is the replacement part for 433 MHz wireless fish finder. 
The Operating Frequency is 125 kHz. 
Operating Range upto 180 meters depending on which fish finder you are using it with.
This replacement sensor has built-in Water Temperature Sensor which is compatible with fish finder with Temperature detecting function. 
Battery life 550 hours
 
Specification
Wireless Frequency: 433 MHz 
Operating Frequency: 125 kHz 
Wireless Sensor Coverage: 90 degrees beam angle 
Depth Range: 0.6 ~ 35 Meters (2 ~ 115 Feet) 
Wireless Operation Range: 180 Metres 
Water Temperature Sensor: Included in Wireless Sonar Sensor 
Power (wireless sensor): 1 x 3V CR2032 Button Cell Battery (included) 
Battery life of Wireless Sensor: up to 550 hours in water usage 
Item size: approx. 83 (L) x 55 (W) x 55 (D) mm (3.27' x 2.17' x 2.17' inch) 
Item weight: approx. 42 g (batteries included)