The collar is one of the chunkiest collars around. This is not a big deal on this system, because there is no way you would use this on a dog under 40lb, it is just too strong. It uses a regular 9V battery that is accessed by undoing these screws. You can change the correction level by undoing the cover with a coin and pressing the button underneath. The collar uses both a beep and a vibration to warn the dog before they get a correction. The prongs on the Petsafe Stubborn Dog Fence collar are interchangeable, you can swap out the standard prongs for longer prongs for long hair dogs. Although, as of November 2009 these are something that no longer comes standard with the system and are now an optional extra.
The best feature about this collar is that it can work with the other PetSafe in-ground collars. So you can use this collar on the large dogs (great danes, mastiff) / low pain sensitivity dogs (pit bulls, bulldogs, German shepherds). With small dogs under 12 lbs, you should use the PetSafe Little Dog. For everyone in between, you should use the PetSafe Deluxe collar. All three of these are good collars, each of these let you adjust the correction level independently and they work nicely together.
This is the strongest dog fence correction collar available, so when you get it, start on the lower levels and move up only if your dog is unresponsive to the lower levels.