My puppy outgrew her sling and now she's so brave that she tries to jump out of it. I needed something larger and more secure. She's now 12 weeks and 5 lbs. I did have to roll up a hand towel to fill in the bottom as she sunk to the bottom.
My pup doesn't wear it like all the other dogs in photos. She won't keep her arms in the little arm holes. I read in some reviews that their dogs also don't utilize them.