Built with YETI's popular ice-for-days, tough-as-nails soft cooler engineering, the Hopper M20 Backpack allows for hands-free hauling of refreshments to the jobsite, trail or campsite. The wide-mouth opening provides quick and easy access to contents, then seals securely using a HydroLok zipper — the toughest, highest-performing waterproof and leak-proof cooler zipper in the world. The waterproof, high-density fabric exterior resists mildew, punctures and UV rays, while thick foam insulation delivers impressive cold-holding capabilities. For ultimate ice retention, add a large YETI Thin ICE pack (not included) to the bottom of the bag.