I purchased a pet ramp first time around....worthless waste of money.  These steps are the way to go.  My dogs weren't skeptical or scared of them like they were the ramp.  Went right up and down without hesitation, and no slippery surface like the ramp, either!!  if you're looking for something to use with an SUV, or VAN, don't waste your money on a ramp, buy these steps.  Holds up to 150 lbs. and does not shake when used.  My pups are both over 85 lbs.