For the aggressive backcountry snowmobiler the Evolve bib pairs up perfectly with our Evolve jacket. Two products designed to fit and function as one. The Evolve bib features a mid-rise front and rear bib for snow blocking comfort. Featuring fully seam sealed 5TECH fabric, the Evolve is the ultimate in weatherproof & wearability. Its shell construction works perfectly with your 509 base layers for ultimate versatility.