Comfy and Soft: Made from 100% organic cotton, our baby sleep sacks are super breathable, lightweight and machine washable. The sleeveless design and TOG 0.5 keep your baby warm and cozy while also reducing the risk of overheating. | Smooth 2-Way Zipper: Our sleep sack double zipper makes midnight diaper change easily. The interior zipper guard and top zipper cover protect any scratches or discomfort from baby's delicate skins, ensuring the safety of your beloved baby. | Roomy Places: The arm and neck openings sized for a perfect fit, the leg room carefully sized for baby to move around freely, but cannot be kicked off, so baby stays warm all night. The sleeping sack is great for promoting healthy hip development. | 3-Pack Features: The package comes with 3 pack sleepsack, so that baby always has one to wear to bed. The 3 colors are suitable for both baby boys and girls, which is perfect as baby shower gift or baby registry. | Essential Baby Item: Baby sleep sacks are good for everyday use, it will help baby get longer sound night’s sleep. There are 4 sizes available for your choices. S for 0-6 Months. M for 6-12 Months. L for 12-18 Months. XL for 18-24 Months.