These double-walled glasses are really nice and warm, but after last 2x washing in the dishwasher, in which a glass dawned that little hole that was created when glassblowing. Now I've got water in the hollow chamber. That's not nice! Since this is now happening only after some time, and I no longer have the box, I can not change it. This is really annoying with the hole and as I have read in other reviews, this error should be eliminated in the product.