Color changing ceramic mug is made of heat-sensitive material, resistant to high temperature 320 ?, non-toxic, lead-free, and chromium-free, And has passed U.S. FDA and European LFGB standard tests.Heat Sensitive Coffee Mug is a very interesting mug, the change from black to the scary zombie picture is amazing to watch, great gift for the zombie loving people.Make Your Coffee time more enjoyable. Give your friend or family a cup of hot coffee by regular black mug and within minutes the black was fading away and the zombies were revealed, How interesting it is. To life by some fun