A double breasted suit is pretty serious business. But a lightweight double breasted sport coat? Not so much. Anything but stuffy, it's actually a pretty laid back kind of jacket. Tailored slim with a slightly cropped silhouette, these sporty DBs are cut from lightweight textured cottons and here's the clincher—they're damn comfortable. Who would've thought that your summer knock-around jacket would be of the double-breasted variety? But think about it: They're cool, breathable and easygoing but they also retain the power to be worn in nearly any situation, paired with everything from your trousers and ties to a striped T-shirt and jeans. And these days, there are a handful of stylish options on the market. Here are four of our favorites.