They are called Coffee Joulies and they are coffee beans (fake ones) made from metal with a material in the middle which isn’t harmful.
Basically when dropping the ‘beans’ into say a cup of tea or coffee, it brings the temperature down to a level of drinking but if you don’t drink it straight away it keeps it the same temperature for up to 5 hours!
They are bigger than normal coffee beans and A spokesman said: ‘This material is designed to melt at 140 degrees Fahrenheit, and absorbs a lot of energy as it melts. This is how Joulies cool your coffee down three times faster than normal.
‘Once it reaches this temperature, the special material begins to solidify again, releasing the energy it stored when it melted. This is how Joulies keep your coffee warm twice as long.’