... : about 1500 hoursSurface temperature: 55ºC-70ºCHandy Warmer,it has a light surface,catch only by one ... warm and health.also be sent Elders.This handy warmer can be work to keep warm 20-24 hours ... outdoor work,work on night,work in sea,guard,stand guard, mountaineering,go fishing,skee,etc.when weather being ... be used soon when you added oil.Put handy warmer into clothbag when use over. sell no.006 steel ...