We break out the Marmot Trestles 15 Sleeping Bag after a long, cold day of pounding trails and treat our tired muscles to a cozy, uninterrupted night's slumber. This bag's resilient polyester shell stands up to seasons of abuse, while its synthetic insulation continues to insulate even if we set up on soggy ground. Lofty SpiraFil LT insulation combines hollow fibers and denser, solid synthetic fibers to create a balance of warmth, softness, and compressibility for easy packing, whether we're car camping for the weekend or on a longer adventure.