Rechargeable foot warmer is operated by a wireless remote control while the foot warmer is inside your shoes or boots.4.5 5.5 Inch (Mens)/6 7 Inch(Womens)
Uses high tech wireless thermal technology no wires, extension cords, Velcro Straps or battery strap brackets & no batteries mounted to your ankle, shoe or waist.
Lithium ion polymer batteries embedded in the foot warmer insoles are rechargeable
Adjustable to three temperature settings to warm cold feet by remote control: settings are no heat, medium 100 degees & high 111 degrees
can be recharged up to 500 times using the charger that is included