Fishing hook remover. Place the line in the slot and slide the disgorger along the line until the head on the disgorger engages with the hook. While keeping the line tight, press the hook a little into the mouth of the fish - this will release the hook from the fish and (if the disgorger head has the correct size) fix the point of the hook so it can not hook the fish again while the disgorger and hook is being removed from the fish.

You can print this in ABS, PETG, or another material for outdoor use, and even when printed in PLA it should last for a couple of fishing seasons.

The model has been made to be scaled (40-50% is lower limit). In the picture, the black are not scaled (=100%), the mint is 75% X/Z scaled, and the green is 50% X/Z scaled.