H5-AJ is the first Acronym® accessory made using the remarkable Babyllama Air Jet Wool construction. Minimalist utility and luxury deliver organic comfort and well-being in a way no other beanie can. Loose hollowcore Babyllama fibers are injected into a tubular nylon yarn yielding insulation above and beyond expected volume to weight ratios. So light you will forget you are wearing it. Handmade high-tech.