Corona Extra Beer Gel 16 oz Freezer Mug Filled with non toxic, refreezable crystals Not recommended for Dishwasher or Microwave 16-Ounce mug combines state of the art refreezability with Corona Logos and graphics Place in freezer one hour or more prior to use, when frozen crystals will turn a frosty white color Eliminates the need for ice as the technology keeps drinks "crushed ice" cold for hours without the watered down affect of ice