Our Classic 18 oz. Unbreakable Polycarbonate Plastic Tumbler (Highball) Glasses are made from the same material used to manufacture bullet-proof glass. 6 1/8 inches tall x 3 inches diameter. These clear plastic tumblers are crafted to last year after year, and are microwave- and dishwasher- (top rack, regular or normal cycles only, no heat dry cycle) safe.