I normally don't write reviews, but this is an exception. Everything about this harness's design and construction is flawless. It's obvious how much careful thought has gone into finding the perfect balance between the three basic issues: Ease of connecting the harness to the seat (with our squirmy, post-surgery, 80-pound teenaged German shepherd) while allowing enough freedom of movement so he can sit, lie down, and move his body comfortably, while still restraining him enough to keep him safe. Although he is able to easily lie down, sit, or turn enough to enjoy the window's breeze, during our first ride I realized he was no longer bumping forward and backward when the car braked hard, and I could see how much more comfortable he was than with the previous harness we had used. The use of the seatbelt's shoulder strap so that it functions in the same way it does for humans - allowing movement unless there is a sudden stop, in which case it locks - is such a brilliantly simple idea, it's hard to believe other harnesses don't take advantage of this. But they don't, and I did a ton of research before settling on this. And lastly, the harness itself is extremely comfortable for him, very quick and easy to put on – definitely an issue for our impatient youngster - and has the same thoughtful design. A sturdy 6-inch strap with a leash clip on one end and the clip that connects to the seatbelt connector on the other makes switching from leash to car extremely simple. As well, the connection to the harness swivels side to side as well as up and back – again an oh-so logical idea but one I don’t see in other dog equipment, reducing leash tangles and allowing more freedom of movement for the dog. All the clips are large, easy to quickly grasp and open/close (crucial for arthritic hands like my own), and heavy duty – they will easily outlive both the dog and myself! One more aspect I enjoyed is that, again due to the well-thought-out design, there is plenty of room for me to sit in the backseat with him.