I wore this once when my newborn was born, but since my baby was born in winter, I switched to a warmer sleep sack, so I didn't use this one much and it's in very clean condition. After that, I didn't have any trouble with night waking or the Moro reflex, so I didn't use it and just stored it. I thought it might be about time to use it, and tried to put it on my baby just before they turned 4 months old, but it was obviously too small. I'm selling it in clean condition. I'll give it to someone who needs it. *I'm also selling an unused swaddle, so please feel free to ask about a combined discount.* I've washed it twice, once to pre-wash it and once after the initial wear. There are no noticeable stains, but please understand that this is a personal inspection. There are some fold marks. Immediate purchase is OK. Thank you. The size is S. For newborns to 3-month-old babies. Please check the official website photos for detailed measurements.