We have a dog who is a total escape artist. We have spent nearly $2,000 on fortifications to try to keep her in. We buried 20 pound landscaping bricks along the fence so she could not dig, so she climbed our 6 foot wooden fence to get out! I had used a In-ground fence years ago when I had a 4 foot fence that my lab could jump. It worked like a charm! So, I finally broke down and purchased this one. Easy to install and although our girl got shocked once, she has not gotten loose again in 5 months. She used to get out EVERY day. We give her a treat every time we put the collar on when we have to leave the house. She comes running when we jingle the collar. We did not want to have to resort to shocking her, but she learned after one time and the alternative was her eventually getting run over, stolen, attacked by another dog or taken to the pound. Our PET is SAFE. Thank you!!!