Great ramp.  The ridges provide sure footing for my big girls (90&100 lbs) and they even included training directions for those who need guidance.  Our car is a new Suburban and the back is 44" high so I make sure I am close, we're the ramp to  slip but is so substantial and week designed that I don't that there is a chance of that. I have had telescoping and other folding ramps but this one is far superior. If you love your dog's and value their safety, this ramp is for you.