Product Description Material: Pure cotton Color: Style A, Style B, Style C Size: S size (within 70 cm), M size (70-85 cm), L size (80-90 cm) For Season: Summer Package Content: 1 * sleep sack 1. [Soft and Breathable]: Made from two layers of light and ultra-soft cotton muslin, it offers exceptional breathability for optimal air circulation, reducing the risk of overheating for your baby and ensuring a comfortable sleep 2. [Two-Way Zipper]: You can easily change the baby sleep sack by opening the zipper from the top. The reverse zipper design at the bottom allows changing diapers in the middle of the night while preventing your baby from getting cold 3. [Protective Lid]: With zipper, the protective lid prevents the zipper from scratching your baby. The sleeveless design reduces overheating risk and allows free arm movement for your baby 4. [Spacious and Roomy]: Our sleep sacks are generously sized to fit over nightgowns and precisely designed to allow free leg movement for proper hip development. Small sleep sacks are suitable for infants aged 0-12 months, medium-sized ones for 12-24 months, and large ones for 24-48 months