The UM offering reflect a reuse of some of the Old Derbi designs, they incorporate in some markets either the DOHC 125cc or a SOHC 279cc Zonghen engine.
In the UK they seem to all have a version of a Honda SOHC 125cc water cooled engine. However, they rate the engine at 11kw where Honda rates their engine at 9.8kw? Both are 58x47.
The Piaggio DOHC 125cc is rated at 11kw…