They are slide carbs.
Not sure of the official name but if you talk to the and say slide carbs sure they can help.
They have been doing carbs for very long time and have good rep
Looks like the switch with no on off may be for north America Market.
I have a SRAD which is the same.
That is a grey import from Canada I believe.
My previous SRAD was UK one and had on off on the lights.