This is the one I have. However, I'd suggest a different version of it, as the shapes (while a huge hit for "putting things through holes" or playing a version of peek-a-boo) offer leverage to make climbing onto the counter significantly easier. This vertical bar design is what I would have gone with in retrospect.

I will note that the non-slip mat turned out to be entirely useless for us so far; he's too young to be reasoned with that he's supposed to leave the mat on the stool, and it's easily removable. We just do without with little concern as it's not slippery unless wet, and the fabric back offers the needed protection for that uncommon scenario. Maybe when he's a bit older we can start using it again. He's used it from 10 months and is now 15 months, for reference.