The QuickFish3i has all the benefits of the QuickFish3, plus Eskimo's Insulated Quilted Fabric. This fabric provides warmth inside your shelter when you need it most. In addition to being 35% warmer than non-insulated ice shelters, this QuickFish offers self-tapping ice anchors that are easier to grip and will not bend under pressure, mesh storage pockets, two doors for easy entry and exit, and YKK zippers included on every Eskimo shelter.