The Obermeyer Boy's Thumbs Up Mitten is made with a synthetic leather palm that preserves the mitten in high wear areas. A polyester micro twill fabric is treated with our exclusive HydroBlock® Sport waterproof-breathable coating, and is insulated with polyester. And, to help with getting the mitten on and off, Obermeyer added an easy on-off center closure. Rib knit cuffs and a clip to cuff minimizes the exposure between sleeve to mitten.