Size small, used for two babies. This is the original model so the zipper is much more durable than their new ones. I also think this says 3-6 months while the new model says 4-8 months for this size. My boys loved these. They are tummy sleepers & I loved knowing they had full mobility to roll front to back, but they’d feel secure and warm with their hands in. They also never had issues with their limbs getting stuck in the crib slats. They both wore this brand for almost two years haha. In my opinion, the material piles very quickly so even if you buy it new, it will look faded and worn after just a few washes. See my other Zippadee listings and bundle to save! Low ball offers will be ignored.