Gimo is made of lightweight and recyclable SEBS rubber, free from PVC. The removable lining made of our wool mix will keep the feet warm and comfy. Machine washable. This boot is a great complement to the childs regular autumn/winter wardrobe. As rubber is a material that doesn't breathe, we recommend this shoe only as a compliment for cold rainy and/or slushy days. Guaranteed free of fluorocarbons.When Gimo is used without lining, please supplement with an insole. Also note that the inner dimension will be considerably longer without lining, about 1,7cm.