Sea to Summit's Etherlight sleeping pads have been extremely popular since their introduction. The Air Sprung Cell construction developed by the manufacturer is perhaps the most comfortable sleeping pad design we have tested. This XR Pro model features a heat-reflective layer that returns body warmth and has double the seam strength compared to other versions. There are some pads out there with a lower overall weight, but a bad night of sleep will weigh you down more than a couple of hundred grams of weight difference. It pays off to invest in sleeping comfort! The insulation value of this model (R-value 7.4) is sufficient for year-round use. Unlike sleeping bags, a four-season pad truly serves its purpose in all conditions, not just winter. The stuff sack includes an integrated pump sack, which is a convenient addition. Using it (or a separately purchased pump) is recommended, as blowing air into the pad manually can introduce moisture over time. - Rectangular Large size: lo