Big Agnes Insulated Air Core Sleeping Pad 2.5" thick, 3.5 season Air Core pad filled with PrimaLoft eco synthetic down insulation for a 15 deg. Temperature rating and an R-Value of 4.1. Full length 2.5" thick pad is lightweight at 22 oz. and packs to a small, compact 5" x 9" 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 66" long. Unique construction technique prevents the insulation from shifting inside the air chambers.