What is this?

[nud1e]

I had the '03 R1150GS serviced by a main dealer recently. 250 miles later, the clutch master cylinder was pissing out fluid. When I opened the cylinder, I found the bellows on the right. As you can see it is much larger than the correct bellows on the left.
Can anyone tell me what bike may have used the incorrect bellows?

 

[Kenny Rodkiss]

Your bellows have been contaminated with oil other than brake/clutch fluid.
Any mineral oil will cause this type of swelling of brake/clutch seals and boots.

Has the oil for the 1200 been used by mistake?
1200 does not use normal clutch fluid like your 1150.