If you drive on the right hand road side (America, Canada, Germany, Austria, France, Italy, etc.) the mirror has to be on the left side, then you should order an “L” mirror.
In a country with left hand traffic (England, Ireland, Australia, etc.) then you’ll need an “R” mirror. “L” means left hand “R” means right hand “L+R” means both left and right hand.
Good to know: Mirror legislation
Older vehicles that do not possess an EU registration, require a minimum reflection area of 60cm² (just over 9in.²) on each of their mirrors. An European approval emblem is not absolutely necessary. Current scooter models are all registred according to EU legislation. The mirrors that are attached to them must have EU approval markings.
Mirrors that have less than a 60cm² reflection area or no EU approval markings are not meant for (leagal) road use. The minimum number of mirrors required depends on the first day of registration
before 01.01.1990 1 right hand mirror
since 01.01.1990 max. speed under 100 km/h 1 right hand mirror
since 01.01.1990 max. speed over 100 km/h a mirror each side
* "registered according to EU legislation" are vehicles since 01.10.2005. Check your registration certificate for the EU entry (digit K).