Gastech Advanced Touch Switch he Advances Touch?? The switch is the part of the CNG / LPG Electronic Circuit Unit and is installed in the vehicle dashboard near the driving seat.?? How Switch Works?? The car starts (ignition), the orange light is ON indicating the car is on petrol, As we press accelerator (rpm increases), it automatically switches to CNG as it reaches the set rpm(programmed i.e. 1200 rpm) Greenlights become visible as the car is now running on CNG. The number of lights indicates the quantity of CNG available in the gas cylinder. Even if CNG is still available in a gas cylinder and you want to switch to petrol, then just press the switch once. It will be switched to petrol. You will not feel any knocking during fuel conversions. End of CNG Indication When the red light becomes visible, it means that CNG is in its last phase. It will still run a few Km???s. 