This counter can be easily clipped to blank of the rod. The measurement scale is from 0 to 999 meters. You can use it both for sea fishing and freshwater fishing. And how does it work? Firstly you drop the fishing liner into depth or cast the bait to certain distance. After that you place counter on the blank of rod. One loop of the liner has to be inserted to rotating wheel. Now you can reset the counter and reel.