BIOME INSULATED JACKET WITH THERMORE ECODOWN Portal Biome Insulated Jacket Black Beauty Outsiders Store UK PORTAL Biome Recycled Ripstop Hooded Jacket for Men MR PORTER Portal Biome Insulated Jacket Black Beauty Goodhood. A serious jacket for the perilous winter weather, the Biome Insulated Jacket from Portal is ideal for baltic rambles and post ride wind downs. Encased in hardy nylon ripstop is Thermore Ecodown insulation, a synthetic material designed to replicate the feeling and warmth of down without any of the drawbacks. Its also incredibly light for synthetic, meaning it can be stashed in packs or bike bags without much fuss. Details wise, Portal has kept things streamlined, opting only to deploy a drawcord hood, a triptych of zipped pockets and a drawcord hem for absolute simplicity.