After our senior dog with his well-deserved twelve years of life, not too much force has to jump up in the hind legs to our high SUV, we decided due to the good reviews this Trixie to order 3939 ramp. Delivery was very fast, ramp was packaged very well. After 3-time practicing it takes our dog now awesome, you get the feeling it would be to run it. If the ramp is not ready on the sill, he looks at us questioningly, Hi folks you have forgotten what :-)