This exclusive design eliminates restrictions and tugging that occur in the shoulders of ordinary jackets. By carefully constructing the shoulder, armhole, and underarm panels, more space is created for easier arm movement The layering system that we introduced years ago continues to be a popular feature giving you three jackets for the price of one. The shell and liner zip together for one maximum-protection parka or zip apart to be worn separately. The result is a system that provides excellent adaptability for all weather conditions or activity levels. Women's TECH Columbia Interchange System Detachable Hood Radial Sleeve Articulated Elbow Underarm Zipper Vents Insulated Lift Ticket D-ring Multi-function Pockets Authentic Fit Powder skirt Critically seam sealed Underarm venting Detachable hood Liner: Lower hand warming pockets Sleeve audio player pocket Mitten sleeve cuff