I bought this one and it works, perfectly.
Its worth noting that there are a few configurations. Some of them have the control wire entering the display from the top, others from the back. Buy whatever one fits best , for your situation.
I chose "back" since I have the Ninja 1000 and put it on my dash.
Mine was 100% plug-n-play.
The have a delayed response, and I'l explain. Many bikes come with a real gear indicator
and those have a built in system for determining what gear the bike is in....like my old 2003 sv 650. That bike could sit on its sidestand and its indicator would keep track of the exact gear it was in.
Not so with this type. These plug into the diagnostic port under the seat. They work by calculating speed and rpm. So, it basically says that at "X" speed, and "Y" rpm, the bike HAS to be in gear "Z"
That works well until you change a front or rear sprocket size. If you change enough, then it may display an incorrect gear.
Lots of them have a custom tuning mode. Be sure yours has that if you have changed sprockets. Mine is still dead on with my 190/55 rear tire.
The muted response is no big deal. You ride along and the display says "1"....you pull in clutch, and shift to second. The display does not show gear "2" until you let the clutch back out.
No big deal, and its a cool accessory. I've tried to fool mine, but have failed every time. The thing just works.