Ghostbusters Heat Reveal Ceramic Coffee Mug With Classic No Ghost Logo The mugs hold up to 11 ounces of liquid. Made from quality ceramic with black glaze and a thermochromic coating. The no-ghost symbol appears after 30 seconds and is visible for up to 30 minutes. Features the international no symbol and the catchphrase "Who ya gonna call?" When hot liquid is added, the famous cartoon ghost emerges, and the title Ghostbusters appears below the no-ghost symbol.