The Helium Down Hoodie takes durable lightweight warmth to a new level. Its secret sauce is Pertex® Quantum with Diamond Fuse Technology, which protects the 800+ fill down with an exceptionally durable and abrasion resistant shell without adding weight. The Helium Down Hoodie even uses an exclusive waterproof version of Pertex® Shield with Diamond Fuse fabric on hood and shoulders for added weather invincibility.