... :circular lace,rectangle,carton FOB USD:4 long time hand warmer1) usage:To charge the electric warmer ... the water is boiling 2)venting:after reuse many time ,venting it ,will use longer 3)model: ... use the winter ,the electric heating warmer can be used to warm hand, warm winter feet ,warm neck ... heating agent, the heating temperature quickly one-time water injection, permanent use, unique explosion-proof