Coincidentally, I should have mine by this weekend. I think I have it correct, but it is plenty confusing. Essentially, there is a threaded mount part number and a rubber mount part number.
But... There are a pretty amazing array of combinations on Monster 821/1200's depending on your model, what country you purchased it in, etc.
I have a US 1200S Stripe, which is an oddball. In the US, the fronts are fork tube mounted in the states (threaded connector). I would prefer to use the Euro and rest of the world headlight bucket mount (also threaded). I understand the threaded connector part number comes with a few adapters to allow me to do the headlight bucket mount, we'll see.
Now, on the back, "normal" 1200S models (in the states, not sure elsewhere) have rubber mount signals. However, the 1200S "Stripe" has the Ducati Performance license plate re-locator as standard, which requires the threaded signals... Except it really doesn't.
The stripe version of the re-locator has most of the same parts as the aftermarket DP kit, but the plate that mounts the tag and the signals is different (presumably government nanny approved), is made of plastic rather than aluminum, and takes the rubber mount signals.
Not much info on an 821, which has a still different way to mount the signals, but judging by the picture, it looks like rubber mount on the rear. I think the fronts are the same as the 1200, so (probably) threaded ones there, but I'm guessing on that one.
Both the rubber mount and threaded DP ones are staggeringly expensive (I'm a little embarrassed buying them to be honest), but I really haven't seen an aftermarket one I like better (many of which AREN'T plug and play), and those aftermarket ones are not exactly cheap either.
Who would have thought turn signals could be so complicated?