I very rarely park my Tuono anywhere, choosing to ride it strictly for fun, not errands etc. I broke my rule one time, for five minutes while I went into a fastener store and some Fricktard stole my clutch reservoir cover. WTF. A week before someone took my buddies rear brake reservoir cover. Apparently it is the fun new thing for kids to do.
so, my question is, as I have never replaced one, what size is it? Is it generic to other bikes too? Seems to be about 31mm wide? Any help is great, I would even be happy to buy a used one from a member!

Thanks!