Grohe Blue Cleaning Cartridge Adapter 40694GROHE Blue cleaning cartridge adapter for multiple usage The swift and simple way to clean your GROHE Blue system! Pair this vital adapter with the GROHE Blue cleaning cartridge (40434001) for perfect cleaning power. Buy it once and then reuse it as many times as you want to keep your GROHE Blue working perfectly and delivering pure and delicious tasting water straight from the tap. N. B. You can't use the cleaning cartridge without the adapter.