Extension Cords permit attachment of Battery Packs at waist (80cm) or chest (120cm), run underneath pant leg, and plug into Insoles. HOTRONIC'S FOOTWARMING SYSTEM With four (4) cells in each Battery Pack, the Power Plus e4 is Hotronic's most powerful, longest lasting FootWarmer! Easily installs in all types of footwear. Transfers simply from one pair of footwear to another. Use while skiing, snowboarding, bicycling, horseback riding, fishing, and during other general cold-temperature activities. AN ELEMENT OF HEAT By blocking and neutralizing the penetrating cold, Hotronic's Heating Element keeps the blood circulation open while maintaining comfort and warmth in the feet. The Heating Element's large oval shape and self adhesive backing provides effective anatomical coverage of the toes and easily installs in Hotronic's Heat Ready Insoles or on insoles of one's own choice. SET FOR COMFORT & WARMTH The Hotronic FootWarmer offers three base level settings for comfort and warmth maintenance. A fourth setting offers an extra blast of heat when needed. Press-hold-and- release the Battery Pack's ON or OFF button to select each setting. Easy to read LED lights indicate the setting selected and when the power is on or off. READY FOR THE COLD Hotronic's e Series FootWarmers, designed for cold temperature operation, maintain up to 70% of their charge after twelve (12) months of non-use! That's power when needed most! NiMH batteries do NOT have a "memory effect" and do NOT require fully discharging before fully recharging. WHEREVER YOU GO Hotronic's FootWarmers easily install in all types of footwear and transfer simply from one pair to another. Use while skiing, snowboarding, snowshoeing, bicycling, horseback riding, fishing, and during other general cold temperature activities.