Fibre-Metal by Honeywelll SWHH1 HotHands Heat Packs, Large Soft comfortable lining traps warmth for protection over a wide range of temperatures Adding UltraWarm heatpacks adds warmth from 130 to 140 degrees over a full work day Use air activated natural ingredients to heat by oxidation It is used in vests, shirt pockets and coat It comes with polybag packaging