It is a sleeping vest that is light and warm. The polka dot print creates a cute atmosphere Made with 100% bamboo cotton. Bamboo is 40% more absorbent than even the finest organic cotton. This means that it brilliantly wicks moisture away from the skin and is extremely comfortable. The clever, breathable bamboo fabric is exceptionally good in a wide range of temperatures, so that wearers can relax and be nice and cool in the summer and feel cozy and warm in the winter months.