The reference number (Ref.) is a value that refers to driving lamps. According to ECE regulation, this reference number must not exceed the upper limit of 100 per vehicle.
The two values of the standard main beam (left and right main headlamp) are counted here plus the values of other mounted main beam headlamps.
The value is entered on the lens of approved headlamps. This means that if 4 headlamps with a reference number of 25 each are installed, the lower two must go out when switched on. Then there are no problems.
If you do not couple it with the normal high beam and put it on an extra switch, you should note the following. The switch or the display in the vehicle must light up blue and be in the driver's direct field of vision.
