Dynamicx makes great stuff. They have neat tambourines!
In all the mountable tambourine at wwbw.com that I have seen, the mounting bracket cannot be removed, but it looks like this one can. It appears to be a handheld tamb with a mounting bracket bolted to it. I think you can remove it with a wrench – not something to do between sets, but it looks to be fairly easily convertible.
I heard that the triangular shape gives it a darker, drier sound. As far as sound goes, the best sounding one I have ever heard is LP Cyclops with brass dimpled jingles. It practically sounds EQ’d. It’s the opposite of harsh sounding. I know they make a mounted version but all I could find is the hand held one.