Our USB hand warmers are infrared heaters and provide "infrared heat" therapy for computer users with hand pain and cold hands. ValueRays® USB infrared heated warm mouse, heated mousepad, heated keyboard pad and Mouse Hand Warmer® provide deep penetrating infrared heat for the cold mouse hand and cold keyboard hands. ValueRays® USB Hand Warmers provide a healthy way to use the computer! Make the computer work for you, not harm you! Reduce stress. Improve circulation. Keep warm!