I still zurückgeschckt him because he did not for Leifheit 59110 Professional built-in washer fits 35 cm.
The internal dimensions are on the ground just 30x18cm (height 24cm) and thus can no longer be the built-in washer rinse well.
I have now instead the Leifheit 55273 buckets EcoPerfect ordered, which is 50cm wide.
For the Leifheit 59110 Professional built-in washer 35 cm of the bucket should be at least 40cm wide (width measured in the dry state 39 cm). Hopefully this info will save a few others a false order!