More Heat, Less Waste. Ignik 10-Hour Resealable Multiple-Use Hand Warmers are made from biodegradable materials, and come in recyclable packaging for more heat, with less waste. Each air-activated warmer provides up to 10 hours of heat that can be used all at once or "paused" and used in increments. Allocate your 10 hours of heat across three days of by resealing in the included AirBarrier Pouch, which minimizes air permeability, and can save unused warmer heat for up to 72 hours -- use on a jog or while walking the dog and reseal for use the next day. Ignik heat is provided by 98 percent biodegradable natural minerals, combined with oxygen, and the contents of the warmers can be composted after use. Ideal for camping, hiking, hunting, snowshoeing, skiing, dog walking, and other cold weather outings, Ignik's ultra-efficient warmers are easily activated by removing them from the packaging and exposing them to air. Each multiple-use warmer measures 2 x 3.7 inches, and weighs 45 grams. Ignik 10-Hour High-Performance Hand Warmers are available in packs of 10 pairs, 20 pairs, or 30 pairs.