Internal battery set with charger for your toslon depth gauge (TF500, TF520, TF640, TF650, TF740, TF750, etc).
No more hassle with loose batteries in your echo sounder with this set you can also do another much longer and when it is empty fast recharge by matching fast charger.
Includes toslon connector to connect directly to your depth gauge screen!
!Warning! The internal batterypack only fits latest toslon models