Yes, 3 keys are supplied with the cylinder.

I also had an EU lock cylinder in my front door (Winkhaus lock with low security level). The ULTRA was perfect for me for several reasons A) Finally a reasonable Swiss Made security lock B) More compact height than the PRO C) My Winkhaus lock could not be opened from the outside when a key was inserted inside - the problem is now also solved with the new lock cylinder. Installation was absolutely hassle-free with the NUKI online instructions. Teaching the app and integration into Apple HomeKit was also absolutely unproblematic. => I am completely satisfied

You need to check that the cylinder is European. On the smart Look Ultra or pro model, there is a version with the cylinder, which is Swiss-made and therefore secure. There is also an indication provided by Nuki as to whether the cylinder is suitable for the lock.

Yes, the cylinder and three keys are supplied. An ID card can be used to order additional keys.
The lock is supplied with an EU (swiss made) cylinder with security level 3 out of 4 (EN 1303 and DYN 18252 certification).
https://nuki.io/de-ch...
NB: The CH cylinder is not yet available.