Montbell has adapted a classic tailor’s trick by integrating a woven fabric “cut on the bias”. By orienting the fabric’s warp and weft threads at 45 degrees to most major seam lines the sleeping bag becomes more fluid or elastic in nature. Additionally, to create an even more comfortable system we utilize an elastic stitch technique to create small “gathers” in the quilting. By combining the strategic seam orientation and the elasticized gathers we offer unrivaled fit and comfort. These innovations allow the sleeping bag to stretch with you as you change positions throughout the night, drawing the insulation closer to your body and eliminating drafty dead spaces. By using a sleeping bag with Super Spiral technology you keep body heat inside your sleeping bag, where it belongs.