Had only concerns, as the set is not glass but plastic, but they were totally unfounded.
Workmanship is very good, we (women) noted no difference from glass heads the cupping.
Small deduction: valves open too easily, instructions are not in German, packaging is not so hot (but with luggage it gets more expensive halt again :-)
And one more tip: let the best cupping the adapter on the minds, since otherwise accidentally open the valve.