Grohe Hand shower Vitalio SmartActive Cube 130

Which of the 20 water-saving shower heads tested are the best? How much do they save in litres and euros? Is showering with the water savers at all pleasant, do they rinse out shampoo quickly and conveniently? Questions like these are answered by Stiftung Warentest. The hand showers tested cost between 10 and 130 euros...