Heat Factory Mini Warmers (Pair) Mini Warmers last 10+ hours and are the most popular size. They are ideal for gloves, pockets, Heat Factory headwear, or any place where soothing heat is desired. Keep handy in luggage, car, or gear bags for anytime use. Sold as pairs ONLY. The Heat Factory warmer is a soft, light-weight pouch containing an inert mixture of iron powder, charcoal, salt, water and vermiculite. When exposed to air, a natural exothermic reaction generates consistent and prolonged heat. The pouch is made of soft cloth lined with a very thin layer of porous plastic for maximum durability. The warmers are odorless, non-toxic and air-activated. HEIGHT (IN) WIDTH (IN) DEPTH (IN) WEIGHT 2.25 3.5 .25 .2 oz.