... about 1500 hoursSurface temperature: 55ºC-70ºCHandy Warmer,it has a light surface,catch only by one hand ... .Use:keep warm to leave cold,it suits common life when weather turn cold,outdoor and work in open ... country,outdoor sport,go out for travel.it is a ... to use:1.open the cover of warmer2.put it up lightly.Don’t touch platinum catalyst3.Put kerosene into ...