I needed a co-sleeper for my tiny, medically complex 3 year old to sleep within arms reach, and all the typical baby co-sleepers would have been too small. This works perfectly! It’s almost the size of a regular crib, so I bought a foam crib mattress, unzipped the cover, and trimmed the foam down a little. I wouldn’t recommend doing this for an infant, but I was making it work for a 3 year old, and the setup has already allowed me to get more sleep.