You've never had a jacket like this before: every design detail also helps makes you better. The pattern on the sides? That's strategically-placed mesh to give you the right ventilation. That longer hem in the back? That gives you the coverage you need when you're moving. It's also weightlessly wind- and water-resistant for protection when the weather turns. Long story short, this is what 20 years of Under Armour innovation gets you: the perfect jacket.