Discover the Diving Ducks Sleep Sack for babies, the ultimate comfort with our buttery soft sleep sacks, designed for cozy nights! Featuring 2-way zippers and the softest materials, these sleep sacks are available in .5 TOG and 1 TOG for customizable warmth. Perfect for your little one’s restful sleep, these will quickly become a bedtime favorite! What is TOG? It stands for Thermal Overall Grade and essentially it measures warmth and how quickly fabrics use heat. Choose your TOG based on the ambient temperature of your nursery. 69-73 degrees = 1 TOG (cooler months) | 74-78 degrees = .5 TOG (warmer months). Always monitor your baby when using sleep sacks to ensure their body is at the correct temperature. Some type of clothing should always be worn under sleep sacks. Material: blend of bamboo and spandex