Under Armour Unstoppable Jacket If you're looking for a jacket you can actually train in on cold, wet days-you found it. Super-light and stretchy, rain rolls right off, and it keeps you warm but not hot. Stretch-woven, this jacket is comfortable and features 4-way stretch for maximum mobility. It is water-resistant, beading water off the surface so you stay dry. The shaped hem and cuffs and hood ensure comfort and provide maximum coverage from the elements. The full-length zip allows for easy on/off and venting, whilst the secure zippered pockets keep valuables safe. Bungee adjusts at the hood opening and bottom hem ensure easy adjustability​ and a secure fit.