Arc'teryx Fission SV Mitten - 2026The Fission SV Mitten keeps your hands warm without slowing you down on transitions or compromising the precision you need to buckle boots and zip up pockets. Finished with precise articulation for more dexterity, a double weave softshell for added wind protection, water repellence, and abrasion resistance, and insulated with extra warm recycled Coreloft, this is our warmest technical mitten. What's been updated: Updated with a more durable double