When unpacking you realize though that lies not much technology behind it and the processing somewhere in Asia has its origin, but it should be assumed at this price. Concerns I had initially only at the "locking cylinder".
The installation is fairly simple, as you can either screws or glue. A template for drilling lies. I opted for the adhesive version because my landlord would probably not so excited when I anbohre his door. For mounting on the concrete anchors are missing, but the screws were probably too small for each anchor.
The battery compartment is secured by a screw, which makes it difficult to remove the batteries a little, but I think that even without a professional screwdriver the tray can break pretty quickly.
The settings "Delayed alarm" and "immediate alarm" can be easily select by the slide switch. Too bad I find that you can not change a little delay.
In the first test, everything went einwandtfrei.
In practice, there is a clear recommendation:
The delay of the alarm is about 15sec, this is quite some time if you have not at hand the key to the alarm.
My wife had the key not on your keyring but in your pocket. (Typical women handbag with chaos) Good thing it was not the middle of the night, because until the key was found due to its size already sounded the alarm minutes. Added to this was already a bit shaky grasp the the locking mechanism and the key.
=> One should alarm key so already in your hand before you open the door, otherwise the time is damn CBA
Conclusion:
for small money a very good solution, Allerding far from professional equipment
suitable as a last resort or for bridging well.
UPDATE: instead of the included adhesive strips should still tighten the unit prefer. Tonight I was awakened by the alarm since the device of the door broke. Apparently the glue was not strong enough.