Thermarest trail king sv self inflating backpacking mattress macaw print the fastest self inflating backpacking mattress by combining our speedvalve tm technology with airframe tm construction weve created a backpacking mattress that inflates in a matter of seconds plus thanks to the auto reversing speedvalve the mattress deflates at remarkable speeds this unprecedented ease of use is fused with 25 inches of ultra supportive loft and an r value of 18 making the trail king sv a re