Our departed Husky, Storm, could dig out of our yard with a 6 foot privacy fence in about 45 seconds...we added an invisible fence on the inside of our yard to keep her in...but she learned how to jump past the 4 feet of shock value, and dig, with only a few shocks (not really shock, but warning beeps, and she had such a thick neck, i'm not sure she ever felt it), so regardless of the cost and extra effort installing and training, she didn't care...took the pain, and still dug out. Any automatic device, whether it's shock or a pinch collar, does not replace plain old attention to your dog. My 3 got out of our yard about a month ago when one fence panel was ripped out during a wind storm and i got up to let them out in the middle of the night. Had no idea the fence was gone, and couldn't see it till it was too late. The boys came back within minutes, but our little girl, Jessy was gone for 5 hours, in the dark for most of it, and crossed 2 very busy roads, and ended up somewhere we would never have looked because none of the dogs ever went in that direction. Thank goodness for the lady that found her drinking in her front yard water feature and that Jessy loves everyone and stayed with her until she called us and we got there...it's a terrible feeling to lose your dog, and while this has been hashed over and over here, I personally, will never ever let my dogs off lead, nor will they ever be out in my own safe fenced yard without being supervised. Just my humble thought.