Assuming it is an led indicator they are about £38 from a dealer , £40 s/hand off e bay from a certain BMW specialist ? , £19 from Motorworks , there was someone on here a while ago selling pairs for £25 or £30.
Fit front indicator protectors , I did after one was snapped off my gsa on the ferry last year
GS led indicators are short version all around , gsa uses short ones on the front and longer stem ones on the rear , but you can fit front pattern ones on the rear of a gsa to tuck them in out of harms way
I had one snapped off on the ferry, I bought a couple of new ones when I get back from a long trip a couple of years ago, I’ve since fitted guards.
I think it happened when people walk between the bikes when strapped down..
There is a link to the indicators in the for sale section if u search it..