I first used this without instructions and could not figure it out. A quick email to greenlee had me the instructions.

Quick start tips.

Plug in the transmitter.

Find panel in high mode, then turn it to low mode, hold the reciever sideways and run down all the breakers once. You must run down all the breakers!!!! Do it toward the outside of the breaker away from the handle.

You may see it hit on more than one, do not worry.

Now go down all the breakers a second time. Make sure you do all of them!!!!
It should hit on one. Go back to that one to confirm.

Do not under any conditions hit the buttons to reset it while doing the above.

The above assumes the power is on.

The reason for all this is it has an automatic gain control and constantly compares each signal it gets until it finds the strongest.

If you have multiple panels hit on high mode its best to run down in every panel. Do not hit the reset button between panels!!!!

Disclaimer, I do not work for greenlee, the above is a much shortened version of the offical instructions, do not flip off any breakers without warning people, blah blah.