I have a '13. The chrome exhaust tips on mine rotted out from the inside after a few years. Honda wouldn't cover them on extended warranty, and a gl1800 owners group gave me a set he had left over from a regular GL1800 Wing. They fit no problemo. I then painted the mufflers/tips black, I think they look better..
I brought a pair of black pipes from a lady that put on 2BR. I "think" they came off a '16 = And yes, they are a tad louder, didn't check the diameter but they fit my '13 perfect, right down to the front heat shield.