There is an enormous difference between cheap plastic and STRAHL polycarbonate products. The difference is in the detail. Yes, the moulding dies are mirror-finished and polished, bet that is fairly common. What is not common is the fact that only Beyer (German) virgin polycarbonate pallets are used in the moulding process. Once the products have been moulded, they are removed by hand from the moulds and heat treated. This process takes stresses out of the moulding and actually hardens the plastic further. The difference is that the product will withstand 2000 dishwasher cycles, top OR bottom of the dishwasher. The only reason this product will not maintain its glass-like appearance is if you were rash enough to use a scouring pad on them. Suggestion. Only clean them in a dishwasher or a very soft cotton cloth with mild detergent in lukewarm water. The tumblers and wineglasses have a weighty 'heft' which is no accident, either. The actual wall thickness increases Height : 120.0mm Weight : 240.0g Liquid Volume : 388.0ml Diameter : 90.0mm Colour : Colourless Type : Wine Glass Material : Polycarbonate Amount of Pieces : 1