The Burton Mens AK BK Insulator Jacket works as a serious mid-layer piece when the temps get brutally cold, a bomber outer layer when the temps are a bit cold, and your go-to piece for bar-hopping after the ride. Unlike those ultra-puffy down jackets which dont even let you move around to strap in and ride, this Burton jacket features low-profile construction and still maintains the warmth of high-loft 700-fill down. Not to mention the soft, warm, polyester lining.