What exactly is the difference between this product and the one with item number 13178673? That you get one more brush head and pay a total of CHF 190 for it? https://www.galaxus.ch/de/s6/product/philips-sonicare-diamondclean-9000-elektrische-zahnbuerste-13178673. Actually, both devices should support the Sonicare app, as they belong to the Diamond Clean 9000 line, correct?