He used to run away anytime he made it outside of the house without a leash. Now, he gets to play outside with his buddy, Ollie off the leash, and still comes back when he's supposed to.
It's awesome, and not too harsh. Also, it has a 2 mile range. Try running away now sucka! ;)
I have 2 other systems that I'm selling if you're interested (bought them by accident). They're Sportdog 3400 series, multi dog systems, and I'm asking 200 each.
They rock...you should buy one!