4- Select the Circular Gauge menu again and choose the
led_blue.png in
circular_gauges_pack 
5- bring the new object at the center and open the properties
set the telemetry field to Engine RPM
Max Field to Max Enginge RPM
Force Max value to 0
alpha at 100%
untick Reverse

6- get the same visible area as the previous object
TIP: play with the transparency (alpha slider), move object, zoom, etc. until both circular objects match
7- save the page and enter the track on your favorite simulation game to see your cool Circular Gauge in action
