Thermarest 40th Anniversary Edition Sleeping Mat Therm-a-Rest patented first self-inflating air mattress in 1972; 40th anniversary limited edition has original logo and color, with current features Inner foam core is lightest, most compressible foam company has produced, reducing weight and bulk without sacrificing performance; stuff sack and repair kit included 70-denier nylon soft grip bottom fabric and 75-denier hex rip polyester top fabric; diagonal punched urethane foam core; two-inch thickness and an R-value of 4.0; made in Seattle, Washington Size S has one-pound, one-ounce weight and 3,936-cubic-inch volume; size R has one-pound, eight-ounce weight and 5,923-cubic-inch volume; size L has two-pound weight and 6,237-cubic-inch volume Includes limited lifetime manufacturer's warranty