The Infiniti X1 features Xcel's easiest on/off front entry system, and all new TDC Thermo Dry Celliant in the front and back chest (torso). TDC is a revolutionary inner lining with smart fibers that recycle your body heat into infrared energy for greater warmth, increased endurance, faster recovery, and enhanced overall performance. Premium seam and fit innovations make the Infiniti a must have for staying warm and comfortable.