I don't know the difference Mark. Couldn't tell you which was the SX/XC/EXC model, it was orange.
The rider at first said he remembered hearing the clang as it fell off, then couldn't remember if he had put it on in the first place, but I think he has searched the shed and come up empty.
Ive lost one of them in the past, and they 'aint cheap!! The quick release D-zues fastner is great for cleaning but mines firmly cable tied in place for when i ride! One tie through the D-zeus fastner and one each side to the frame rails under the engine ;0)