My 6 month old pup behaves very well already. Mostly just bought it incase she gets too far a way I can either buzz or ding her. After 2 zaps on only 20 power out of 99, she only needs a vibration if she's going to far or doing something she's not supposed to. I have yet to test the distance to its full 1200 but its definitely good around my back yard (think roughly 500 ft). Would highly recommend this collar.