Question about Lelit Water filter (2x70 litres)

This filter is specially made to fit well in the tank of the Lelit machines. Take a look at the manual for the Lelit Mara X, for example, to see how the filter should be inserted.
I would definitely use a filter. But it can also be a Brita system, with which you fill the already filtered water into the tank.
Without a filter, you risk calcification and less taste.

Fits most machines. The diameter of the hose is important.

Do not buy. Use a table water filter