There is a wire which you have to connect to either say a switch on clutch pedal or a steering wheel switch.

The launch control is set electronically, and when you use full throttle change it cuts down to your preset launch control value, which personally IMO isn't very good.

If you were to buy say an Armtech one, they aren't set digitially, but the launch control and full throttle change operate at whatever the rpm is when the switch is depressed, so the benefit being if you have a very low launch control RPM you could lose out with the way the Omex works.