It?s important to get your little one fully relaxed for bedtime so that everyone gets a good night?s sleep. Our breathable sleeping suits and snugly and soft, gentle on your baby?s skin and adaptable to temperature changes throughout the night. Four layers bamboo cotton muslin fabric (a blend of 70% bamboo, 30% cotton) and 100% Sorona(http://sorona.com/our-story/) filling that creates a luxurious feel. The two-way zipper with protective cover ensures your baby won?t graze their skin on the zipper during sleep. To help parents understand which TOG values are right for different room temperatures see the TOG guideline: 2.5 TOG ideal for room temperatures between 16C to 20C