Electric Scooter in Spain

Hi everyone,

I want to buy an electric scooter (see attached picture) in spain an I need
some legal info about it:
1. Is it legal in Spain ? What is the max legal engine limit (in watts) ?
2. Do I need to wear safety accessories (as helmet, etc...) ?
3. Is it possible to go with this e-scooter everywhere or just on roads/sidewalks ?
4. What does this e-scooter "must have" in order to be legal in spain ?

Any help will be greatly appreciate...

Kind Regards,
Josefin.