A jacket keeps you warm by trapping air (a good insulator) so that you don't lose heat to the environment. When you add more layers, you're essentially adding more insulation and trapping more heat. With the Klymit Ulaar jacket, there's no need to add more layers. It lets you pump air into its patented NobleTek chambers, which gives the jacket a snug fit and keeps you warm even better. Ventilation is enhanced when the jacket is deflated. The Klymit Ulaar aims to keep you “warm and comfortable no matter the weather or what activity you're doing”, said Klymit president Cory Tholl. We think it's a really cool jacket and hope it does well on Kickstarter.