This popular bottle green bottle-opener Guinness cap is both cute and practical. Made from 100% breathable cotton, the cap is sturdy and high-quality, with authentic Guinness embroidery and its trademark Irish harp. Best of all is the bottle opener cleverly embedded on the brim, by far the most useful superpower we've ever witnessed in a hat. (OK, maybe opening beer isn't a superpower. But it's definitely an important skill-set).