Our Cross Insulator Jacket is crafted from water-resistant ripstop down fabric, enclosing 100g Warmcore by PrimaLoft insulation There's a full inside flap, protecting your chin from any abrasion. There's a cinch cord at the bottom hem and elastic at the cuffs. Fully functional as a stand-alone garment, it's thin enough to layer under an outerlayer and compresses easily into your luggage. This is a harness- and pack-compatible design.