I purchased this harness for my dog after he jumped out of a moving car. Thankfully he wasn't injured, but it scared me badly enough that I began having him ride up front, with me, and buckled in with this harness. It's a lot like a regular harness that you would use to walk a dog, though I usually only see larger harnesses like this on smaller dogs. The major difference is that the Four Paws Safety Seat Support Harness has a loop that a seat belt can be pulled through. When the set belt is through the loop and than buckled it makes the dog sit fairly still in the seat. My dog could still put his nose up to the window, but he could no longer try to jump out. I also liked that it was nicely padded. At first I was very happy with this purchase. Unfortunately, after less than six months the harness came apart. It was unusable at that point. I contacted the company because I didn't feel as if their product should have come apart that quickly. Their response was that it was too old for them to replace. I guess this is not meant to last six months.