I've had several of them over the past 5-6 years. The original model had a temp feature that was removed in the newer models. Mine died so I upgraded to a newer model at a reduced cost but lost temp option. They are very basic and I use it on my float tube. I pretty much just use it as a depth guage. It does not show actual contour of bottom. It has basic pictures of botton and fish that it displays. Not the best for detecting fish as it often detects the bottom as fish or weeds. I do not like the long cable for the sensor as I use it close to my tube. Its compact and fits in your float tube pocket. Water resistant but do not dunk it as it will likely not recover. So its a basic depth gauge(99ft max) and can detect fish. I bought mine years ago for $99 and when they break they offer a replacement at reduced costs.. Working on my 3rd unit now. You can use it to find edges and drop offs. Sorry for the so so review but now you know.
Jet
"The charm of fishing is that it is the pursuit of that which is elusive but attainable, a perpetual series of occasions for hope" - unknown author