Ball-end T-handle hex key

Channel leg lock tool. Ball-end makes it easy to insert into lock screw. T-handle makes it easy to tighten and loosen. Long length makes it easy to reach ground-level screw.

If you want Channel legs to be easy to adjust from run to run, leave lock screw almost tight, but not fully locked. About a quarter of a turn usually unlocks the screw just enough. This will allow you to nudge the bottom of the pole with your foot in either direction, closer for more of a challenge, or farther out to help give your dogs more confidence.