The unscrewing the old and screwing on the new handle succeeds without any problems. For the battery compartment on the handle but you need a very small screwdriver. The specified in the product description length of 37mm refers to the way the length of the pin, which is inserted in the door / window (which was not directly clear to us before ordering our first handle).
The alarm is only active when the window / door handle downwards, the door is so tightly closed. When tilted door or cracked window, the alarm can not be activated.
The alarm beeps when you close the door, and thus shows firstly that it is active, and secondly, that the battery still works, so that you always know when the batteries need to be changed.
We have knocked externally firmly against the door frame, to trigger the alarm. This worked well. The alarm is very loud, not very noticeable from the outside, especially in the apartment, but we think that an alarm is not really intended for the neighbors to rouse, but that the burglars quickly look into the distance, as they usually do not pay attention want to attract.
Remarkably, we find it, that the alarm is also triggered if one fist inside beats (large windows, Punching about 1.5m away from the safety handle and not the frame of the window actually secured) against the frame of the adjacent window. One thus needs our opinion no backup for each window a large glass frontage, but can equip all front with only a safety handle and yet feel safe.
All in all, the security alarm handle installed in 5 minutes, works great and makes you feel that the apartment is a bit more secure.
