Rear shock mod

[Giepie]

I just bought another 1150gs, my previous one almost burnt out. (Looks like short at starter). Very neat bike I got. When I inspected the bike at home I saw something funny at the top of the rear shock, there is a valve like a care tyre valve connected. I presume you can pump some extra air in there, probably nitrogen. Any know of such a modification?  Will try to get a pic today.

 

[katana]

 

[Welsh]

 

[Giepie]

 

[Jughead]

 

[Giepie]