Ultra clear 20oz non-fragile double wall glass mug, designed for your everyday use, sturdy and durable. * Made of ultra clear lead-free borosilicate glass, air insulated in the unique double wall struture keeps cold drinks cold and hot drinks hot for a long time * Big Handle design makes it very easy and confortable to hold the mug with full glass of drink * Dishwasher and microwave safe. * High quality build, see warranty info in the manufacture web site