NWT Purchased but never opened. My baby ended up sleeping well on their own. From the website: Our patent-pending Dream Weighted Sleep Sack is designed to help your baby feel calm, fall asleep faster and stay asleep longer. The sack features our exclusive CoverCalm® Technology, evenly distributed weight from your baby’s shoulders to toes, to naturally reduce stress and give your baby the feeling of security and comfort - just like a hug. Size M: 6-12 months Moon Grey