Spring / Summer - 0.5 TOG: shell & lining made from 95% Viscose from Bamboo, 5% SpandexAll Seasons - 1.0 TOG: shell & lining made from 95% Viscose from Bamboo, 5% SpandexFall / Winter - 2.5 TOG: shell & lining made from 95% Viscose from Bamboo, 5% Spandex. Fill made from 100% polyester.Viscose from Bamboo is made by extracting cellulose from wood pulp. Although it is technically a man made fabric, viscose from bamboo is created from natural and sustainable materialsBreathable fabric to keep littles cool in the summer and warm and cozy in the winterThis material is certified by Standard 100 OEKO-TEX® certificate BJ050-196673; which ensures that no hazardous substances are presentTwo-way zipper for easy diaper changing Spring / Summer - 0.5 TOG ideal for room temperatures ranging from 74 - 78 Fahrenheit (23-26 degrees Celsius)All Seasons - 1.0 TOG ideal for room temperatures ranging from 69 - 73 Fahrenheit (21-23 degrees Celsius)Fall / Winter - 2.5 TOG ideal for room temperatures ranging from 61 - 68 Fahrenheit (16-20 degrees Celsius)What is a TOG rating? - TOG stands for Thermal Overall Grade and is a unit of measurement for insulation and warmth of sleepwear. Put simply, the lower the TOG rating the lighter the fabric. The higher the rating, the more padded and insulated it is for warmth.Made with care in Sedex-certified factory WeiFang, ChinaSedex is one of the world's leading ethical trade membership organizations, working with businesses to improve working conditions in global supply chainsHypoallergenicSoft & SilkyBreathable Bamboo Sleep Bag 1.0 TOG