I've recently fitted a Garmin 2610 Street Pilot to my GS. Don't laugh, I like it, and it was very cheap! Can't read the notes in the top of my tankbag any more so I just bang the route into the GPS and away I go- don't need it to do any thinking for me... Anyway, I also bought an earpiece for it which has a 2.5mm stereo jack into a single helmet speaker, plugged it in and unfortunately it doesn't work. Tried it with the (stereo) earphones off my phone and it works fine, though only through one ear. Is the Garmin plug a strange type? I tried pulling the plug out of the socket out slightly but no go.