The rated here cups (Classic espresso cups) with 85 ml of volume, however, are meant to be used for a double espresso. A normal espresso has 25 ml, whereas a Ristretto even only 15 ml. That is, if you wanted to drink only a normal single espresso, rather Ristrettotassen with 70 ml would possibly but recommended volume. Even this would then be filled with an espresso only about one-third. So if you really classic italiensich preferred should rather accept the smaller Ristrettotassen.
Otherwise comply with the cups of the specification and are very nice and thick walls. Could no surface defects or the like discovering.