Designed to meet the needs of mountaineers who routinely spend time in harsh alpine environments, the Mountain Equipment Lightline Down Jacket is designed to shield you from the cold when staying warm isn't just preferable, but essential. The windproof and water resistant DryLite outer shell is packed full of 675 fill down, stitched in horizontal baffles to ensure that the insulation stays where you need it most. The down itself is an incredibly warm 90% down10% feather mixture, which is the warmest downfeather ratio generally commercially available. Mountain Equipment gave the Lightline a fully adjustable zip off hood so you can trim weight if you need to, and used stitched through construction to ensure that it isn't carrying any extra bulk that can be a hassle on serious alpine expeditions. An insulated baffle sits behind the zipper to prevent drafts and heat loss, and the zippered hand pockets are covered by insulated flaps for the same reason.