I bought this product not to torture fish (as I think it is a harmful device for fish), but as a device to lift my Kleen Kanteen out of the hot coals. When opened, and inserted inside of the stainless water bottle,, the wires have enough tension to easily lift a water bottle style container safely out of the coals, seeing as the Kleen Kanteen doesn't have a wire bail.  I'm quite sure it would work perfectly  for what it's intended for, but the sharp points will certainly injure a fishes mouth. If you plan on catch & release fishing, this isn't the tool to use. For that, I would give it ZERO stars!