Big Agnes Air Core Long Rectangular Pad 78in. x 20in. 3 season Air Core pad has a 35 deg. Temperature rating and an R-Value of 1.5. 3.25" thick pad is lightweight at 23oz. and packs to a small, compact 4" x 10". It is about the size of a Nalgene bottle. If used in a Big Agnes sleeping bag, the pad can be deflated, left in the pad sleeve and stuffed in the sleeping bag stuff sack. The rectangular shape is 20" wide x 78" long x 3.25" thick. The I-beam construction technique is functionally superior to the typical welded-through construction of other air mats. Die cut holes in each I-beam allow air to flow freely between chambers giving constant support and comfort.