Grabber Foot Warmers are thin, comfortable air-activated warmers that fit inside your shoe or boot, and provide over 5 hours of soothing warmth beneath your feet. The latest addition to the best-selling Grabber line, Foot Warmers contain a revolutionary warmer technology and are designed for one-time, disposable use. Individual Warmer Specs: Size 3" x 9"/3.5" x 10"Avg Temp 95 FMax Temp 102 Duration 5+ Hours2 Warmers per package Women%u2018s Sizing: S/M - Shoe size: 5-8 M/L - Shoe size: 9+ Men%u2019s Sizing: S/M - Shoe size: 4-7 M/L - Shoe size: 8+