One would be the EU version (ZW090-C: EU frequency - already in place) and the other one the US version (ZW090-A: US Frequency - to be purchased).
Reason of different frequencies needed is installation of US format glass plate touch panel Z-wave switches (via AliExpress) but in the size I need them to replace current analog BTicino wall switches (and be sure the fill the wholes in my walls

required size is 120mm by 74mm (approx.)
example: https://www.aliexpress.com/item/3300237 ... 6731Z7XjcU