Androdz. Not many people using the nitrous button T-handle, I don't think anyone makes a specific T-handle for the S197 (12mm X 1.25) that's why I had to Mcgiver it to fit. I forgot to tell you, I also have an arming switch on the dash for the nitrous alonside the nitrous bottle heater switch.I installed them on the blank plate where the dash light color selector switches go. Mine did not have that option. So not only does the arming switch have to be on, the throttle must be floored and the T-handle button pressed before it will spray. This allows me to spray only when I want and not every time the throttle is floored.