Measure size of kids' hands before buying. Materials: Polyester. Elastic in the wrist area, and the hook & loop allows you to adjust the tightness for your comfort, to make sure that there is not easy to fall off while you doing sports. It has water-resistant polyester fabric outside, and with waterproof membrane inside, to keeps children's hands dry in winter. With anti-lost hook, which you can attach to the other one when you need to take it off. It has water-resistant polyester fabric outside, and with waterproof membrane inside, to keeps children's hands dry in winter.