They are NOT O.E.M.
These makes are never used by Mercedes-Benz or any other vehicle-maker to my knowledge.--They are 'after-market' makes.
There are literally dozens of nozzle-makers supplying the repair sector, some are OK ish, some are downright crap. There are even rip-off Fake Bosch/Delphi nozzles around prolly made in China too, and are reasonably easy to spot.....
Vehicle makers buy the entire injection-system for each vehicle from Injection Equipment Makers like Bosch, Stanadyne, Diesel-Kiki Delphi, Lucas etc.
It would make No Sense for them to buy a pump from Bosch and an Injector Nozzle from monarch when Bosch worked with the vehicle-maker to devise/design the entire system for that particular application, and have designed suitable nozzle for That engine/car/trans combo-
-Who EVER heard of a Bosio or Monarch Injection-Pump on a vehicle!!.
I tried some spurious made nozzles,--more than once over the years--might even have been bosio--They were defo Italian, That I DO remember--They were crap, and I slung them back to the suppliers, and paid a little extra for a Proper make (Bosch).....
Never again. (I keep saying that, But it'll be a year or two before I try them again, as they are Just SO Cheap!...)
Always a Proper Make nozzle, Cant go wrong then, You Know its Correct and OEM.--IF its good enough for Mercedes-Benz, then its good enough for me
Especially considering its a fair bit of work to install them and set pressures correctly--You DONT want to do it twice!
Look at the various posts over the years concerning bosio nozzles lasting only a few thousand-miles before giving faults....
Anyway, This thread was looking at the Types and NOT the Makes of nozzle that have been used....