I was concerned that this might be too small for our 70 pound husky to use to get into the SUV, but it works very well.  He can jump down out of the SUV, but he can't jump in it in his own anymore.  He is a bit uncoordinated while using this pet stair, but he's getting better at it.  This really saves my back because I don't have to lift him into the SUV anymore.

Pros: Easy to assemble.  Very sturdy for a 70 pound dog.
Cons: I wish it were a just a wee bit wider as that would make it easier for our dog.