Therm-ic extension cords for Smartpack or PowerPackWhen the batteries are mounted on the rear of your boots, they can be difficult to access and adjust. When you use an extension cord, you can clip your batteries to your belt or put them in your pockets instead of hanging them on your boots. This makes adjusting your batteries easier and can keep your batteries warmer so they last a longer. •You'll receive two cords per length, one for each boot. •80 cm, (32") cord: used for attaching your batteries to your waist area, top of pants, or your belt. •120 cm, (48") cord: used for attaching your batteries to your chest area, top of your bibs or overalls.