Ergodyne - EGO16995 Made with all-natural ingredients, use the 6995 Foot Warming Packs to protect your feet from harsh cold, hypothermia and frost bite. Warmers retain heat up to 6 hours before replacing. Attach adhesive to your socks for comfortable, long-lasting wear that covers the entire bottom of your foot. Thin design works for most shoe types and sizes for universal use. Warmers are easily activated once they are exposed to air so no battery is needed. Conveniently store packs in work bags or jacket pockets thanks to the portable, compact design. Quickly toss away your disposable pack once it has been used. These nontoxic packs keep you warm and protected in extreme weather conditions while working or even while enjoying recreational activities. Pack includes 20 individually sealed pairs of warmers.