Just like regular Thinsulate™, it is lightweight, breathable and moisture-resistant. But Thinsulate™ Ultra insulation goes one step further. It is loftier and thicker than original Thinsulate™ insulation-for even greater warmth and comfort, yet still thin enough to allow complete freedom of movement. A mid-loft insulation, it is designed for some of the harshest conditions on earth and retains insulating value in damp conditions.
Thinsulate™ insulation works by trapping air molecules between you and the outside. The more air a material traps in a given space, the greater its insulating value. Because the microfibers in Thinsulate insulation are far finer than other fibers, they trap more air in less space, which naturally makes it a better insulator. So we haven't repealed the laws of nature with our thin insulation; we've simply obeyed them better...to your advantage.