The Marmot Women's Trestles 15 Sleeping Bag offers superb value with its toasty warmth and comfort-oriented shape. Its affordable price point sure doesn't hurt either, leaving plenty of extra loot for far-flung trips into the mountains. SpiraFil LT insulation traps thermal warmth with its high-loft synthetic fibers, ensuring we're sleeping soundly when the mercury plunges on crisp, clear evenings. Newly improved over previous versions, the anatomical, 3D-shaped footbox improves warmth and roominess for our feet.