Ready Pulsuhr unfortunately without lighting

I bought this clock more than gimmick and gadget rather than sincere sports companion. I was unaware of looking for a heart rate monitor and have rather made a spontaneous purchase without a direct comparison.
Of course, I use the heart rate monitor now playing sports (jogging) and have to say that me the clock previously excited.
- The clock is lightweight and also looks outside the training mode from well

Positives:
- The clock was easy to adjust. I only had to scroll through the booklet to find out how you can exit the setup menu (long press the Toogle keys).
- The clock communicates very easily and quickly with the chest strap, which I do not even have to moisten.

Negatives:
- The manual is enclosed on a mini-CD. With a slot-in drive you stand there first before a challenge. I had to go in search for a download link to the manual long - for the lack of printed manual there -1 star
- Unfortunately, the clock has no light. I am a regular runner night and can not see the stop time and heart rate during the running - there is of me -1 star
- At 180 cm and 74kg of chest strap slips to lowest setting unfortunately while running slightly
- What I did not realize until now, the individual modes and Auswertebereichte. What is meant by "% in zone" and training "within zones", I can not understand.

Addendum on 01/07/2014: I have now the clock a bit longer in use and has my vote to correct something. Although I have criticized the broad chest, I now have to say, despite weight loss that the belt still fits well, even if he somehow makes it seem to be too loose.
As I have tested the chest at the gym on the cardio machines, I want to set up my rating by 1 star. The belt is detected within a few seconds of the devices of the brand ERGOFIT STEM and can thus serve to use the device for heart rate. At the same time may also still be read on the frequency of the clock.