The q-core SL is basically the popular Big Agnes Q-core built with super light materials (hence the SL tacked on). Instead of the typical tubular design, BA has “quilted” the pad in an effort to provide a more even weight distribution. The pad is built from rip-stop nylon, utilizing the “X-Static” insulation by 3M. It’s basically Thinsulate insulation with a silver lining for more insulation and better antimicrobial properties. Gone are the all brass inflation valves from past pads. Instead now they have a brass core, with plastic housing. The pad weighs in at 1 lb. 2 oz. for the regular length. Dimensions are supposedly(more on that key term later) 72 x 20 x 3.5 inches for the regular size.