Seriously: Opening to the ominous four corners did not work really, but saves me time, and above all nervous, as I with a sharp pair of scissors (important: it must be sharp at the top) on the lower side (where is glued also the scissors icon) individually each plastic tooth and had gradually cut. Then you can open a small flap and manual flying a counter. Only with this and the above shown, individual Master Code (arrows), the lock can be permanently namely from the packaging - otherwise you have no chance! Admittedly, the leaching is therefore quite expensive, but really not unsolvable.
The weight of the castle is approximately 210 grams quite heavy and makes a good impression. After opening it with the Master code, you can (assignable to the arrow keys) program different codes and also change the master code. For this you need several attempts because after 5 seconds Do not enter everything starts from the front, which means you have the keys already know relatively well, so that everything runs smoothly. But is not a problem as you can as often begin with an open lock code storage. Nicely here is to choose the letters, a word as a code.
When closed, the grants only 3 attempts to open it, we do not succeed, you still need a code. This is a good protection for the basement and takes potential thieves limited hours too long. ;-)
The battery life is indicated by 5 years and in time for the death of such should approach warning lights. When it is not aware and the power should be too weak to aufzubekommen the lock, the battery compartment can indeed open only half, but that's enough to "jump-start": Place a suitable button cell to the half-open trade and the energy is sufficient again To open the lock with the code. After that, insert a new button cell.
Conclusion: Massive castle with individually assignable codes (numbers, arrows or words).
