Grabber Mega Warmers, 12+ Hours Maximum Heat- 1 Count Grabber warmers are a non-toxic, odorless heat sources using all natural ingredients that are non-combustible Air-activated instant heat source Simply open the outer package and expose the packet to air. Grabber warmers are pre-mixed so no shaking is necessary For best results, use warmers in an enclosed area with air such as a pocket, glove, shoe or boot