The directions are well written and easy to follow. They offer several options for installation, in ground, above ground, with a fence, around gardens and trees, etc. They are thorough and easy to follow. After installing the unit, I tested it per the instructions and everything was working. There are 5 levels of electric stimulus. The collars are fully adjustable for the shock level, the controller adjusts the distance the collar starts to activate. I bet the reviewers that said their dogs didn't respond probably didn't understand the wall controller does not control the level of shock. The collar has a separate adjustment for the level of shock; 1-5. The wall controller adjusts the width of the zone, 2' wide to 10' wide. If your collar is one level 1 (low) and the width is at 10 (maximum), your dog will not get a shock, only a low level beep. You must adjust the collar to 5 (high) to train the dog the first time. One or two zaps and the dog will learn to associate the warning beep with a zap. Then you adjust the shock level down to 2 or 3 for most dogs; higher for stubborn dogs with thick fur. There are longer (included) contact points for dogs with thick fur (shepherds, collies, etc). the short contacts will not work on dogs with thick fur. If in doubt, try both sets and see if the longer contacts work better. Dogs need a visual barrier, they won't remember the wire is buried, once they associate the visual barrier with the electric fence, your problems are solved.Why is this a 10 star review? One of my dogs was bored and saw the controller and thought it would be a good chew toy. I came home and found it mangled and in 15 pieces strewn across the carpet. When I called to buy a replacement controller, offered to replace it for free! I wasn't expecting that, but I certainly wasn't going to refuse their kind gesture.Thank you .I would have written the same review (5 star) even without the replacement, but they really do stand behind their product even when it obviously wasn't a factory defect and deserve 10 stars.