Grabber warmers offer superior, all-natural, portable heat and are standard equipment for anyone who enjoys outdoor activities when its cold outside! Warmers are air-activated, no shaking or kneading required; just open the package and allow a few minutes to start the process. Grabber Warmers are dry, clean, odorless, non-toxic, non-flammable and designed for one-time, disposable use.Foot warmers are thin, comfortable, and easily fit in your shoe or boot providing over 5 hours of soothing warmth beneath your feet!