The LRT 100 lambda control testing device is a diagnostic and service device for Mercedes Benz cars with KE-resp. LH-injection or 2E-E carburetor. The LRT 100 will digitally display the pulse duty factor at the lambda exit of the control unit. The LRT 100 is connected to the car with the 9-channel diagnosis plug or the 4mm pin plug, both of which are included with the device.