The Grabber Toe Warmer is designed to fit into the toe of your shoe, above or below your foot as your choose. A natural chemical reaction provides six hours of gentle heat. If you wear it above your toes, it also will shield your toes from cold wind going through your shoes. Some people even wear lighter shoes in the winter with the toe warmers tucked inside for extra warmth. Grabber Adhesive Toe Warmers are the perfect everyday solution for cold toes. Featuring a thin unique rounded toe and adhesive backing, they are designed to function in the low oxygen environment of boots and shoes. Simply stick the Warmers to the outside of your sock, under or over your toes, and enjoy more than 6 hours of soothing warmth.Individual Warmer Specs: • Size 3" x 4"• Avg Temp 100 F/38 C• Max Temp 107 F/42 C• Duration 6+ HoursAll Grabber Warmers are designed for one-time, disposable use. Minimum 1x box per order. 40x pairs per box. Don't go for the cheap substitutes which are known to split and not last as long as promised.