New Kelvin Aerolite Technology. In a sea of outdoor specialization, having versatile gear as well is a strength. Synthetic PrimaLoft® Gold Insulation with Cross Core™ technology replicates the aesthetics and performance of down insulation, but with warm-when-wet performance. Lightweight insulation is infused with silica aerogel, a nearly weightless material that’s composed of more than 95% air and acts as additional thermal insulation. Use it for everything from backcountry hunts and off-season scouting trips to everyday life.