Hotronic’s Foot Warmers 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.  Hotronic’s S Series Foot warmer are designed for cold temperature operation even in extreme conditions down to -30C! At the same time, Ni MH batteries do not have a “memory effect” and do not require fully discharging before fully re-charging.  The Hotronic FootWarmer offers three base level settings for comfort and warmth maintenance. A fourth setting offers an extra blast of heat when needed. Easy to read LED lights indicate the setting selected and when the power is on or off.  Wherever one goes worldwide, Hotronic’s advanced global charging technology senses when the batteries are charged and protects them from overcharing damage by switching to trickle current re-charging. Compatible with all S and Prior e and m Series Battery Packs, The recharges LEDs indicate recharging mode and battery charge status.  By blocking and neutralizing the penetrating cold, Hotronic’s Heating Element keeps the blood circulation open while maintaining comfort and warmth in the foot. The Heating Element, with it’s large oval shape and self-adhesive backing, provides effective coverage of the toes.