Similar to other Klymit sleeping pads with a unique cut out design and high pressurized comfort, the big brother Inertia XL is wider and more supportive to accommodate more body shapes and sizes. Klymit uses body mapping to support the key areas, such as the head, hips and feet and removes padding in less critical areas to reduce weight. Cutouts allow a bag's insulation to remain lofted, which maximizes warmth, rather than becoming compacted between your body and the pad. Using dynamic body mapping, V-shape chambers allow articulation of the pad so it stays with you as you move during the night. Inertia X-Frame pad can be inflated with just 4 - 6 breaths; to adjust firmness, use the included hand pump to increase air pressure in pad. Use it under or inside (so you'll never fall off) your sleeping bag. Pad features an integrated pillow/ergonomic head cradle. Rolled up, Klymit Inertia XL sleeping pad is about the size of a 16 oz. water bottle. Pad includes a stuff sack, patch kit and dry air pump. Constructed from 75-denier polyester for durability.