This arm assembly includes the plates, R & L (52471-MKC-A00 and 52472-MKC-A00) and most of the bolts. The whole thing is about $US250. It is a new takeoff, 1 mandatory test mile. I keep a spare one of these, ready to replace every 30k miles while I refresh the one that's on the bike at my leisure. This is one of the least properly maintained areas of the GL1800, the bearings in it are worth $100+