Awesome shock collar. As an avid hunter and dog enthusiast, this collar has dramatically improved my pups behavior and obedience. Has plenty of shock for the largest of bear hounds. I had a problem with one redtick coon hound that wanted to wonder off to the neighboring farm or when a vehicle come up the drive. After 2 days with this system you cant drag that dog around a vehicle or past my property line. Rarely will you have to use the shock system unless they're somewhere they shouldn't be. Most of the time the vibration system and a firm "No" is all that is needed to teach simple discipline such as not jumping, excessive barking, aggressiveness towards other animals, chasing chickens, ect. Some may not like the idea of such as purchase, but I can assure you it hasn't hurt any of my dogs and if you have patience and make the dog understand right from wrong for their safety and yours it is in no way cruel. Within a few days you can have them well trained and to remove the collar. If their behavior problems return put it make on and repeat. Battery on these lasts several days. I love the locking feature, shock dialed up or down for different size dogs, color is strong. Best shock collar I ever owned hands down and that goes for some I've paid up to 150 bucks for. Buy it!