The reflector is quite large for a tail lamp on the mudguard, unfortunately the manufacturer forgot a diffuser at the LED, so that you only have a small point of light. The splash-proof housing is suitable from German production and also for incandescent lamps, why this does not help as a diffuser. Thus, the viewing angle of the LED is quite low (red LED ultra bright 5mm -> 35 ° beam angle). From behind the LED is clearly visible from the side rather not.
The backlight lights up when driving on immediately. Some circuits were needed earlier 50-100m before the 'battery' was charged and the LED lit. Since a capacitor has been installed as 'Battery' (Goldcap 0,33F), one needs replacing batteries. The term of a Goldcap capacitor amounts to approximately 1000 operating hours.
The Prophet diode rear light with parking light is to keep charging about 3-5min. But I have not yet tested by the circuit here but that should go. For a stop at the traffic lights, it has always served me.
Overall, a quality product at a reasonable price of 13 euros. One star deduction for the 'forgotten' diffuser for the LED.
