The installation is very simple: by means of screws base plate to the ceiling - Replace smoke alarms and easily turn - finished.
About a protruding edge on the base plate small strap a switch by rotating folded in smoke detectors - and this is by a short beep and a flashing of a light-emitting diode in the device an activation signal.
Then hold briefly the test button is pressed in the middle - then the actual alarm. Let go and be a little calmer in the event that the device really needs time.
The instructions are simple and well structured.
Networking / Wireless Networking is only relevant if you want to monitor is very spacious premises, where one possibly a detector could not hear anywhere alone.
By networking then beat all alarm, regardless of their own union reports the fire. If you have just a simple apartment or a small house, you can skip this step.
An emergency-test with a smoke detector should naturally not perform!
Please do not smoke out to test the unit with smoke! This harms only the sensor unit, which must be very sensitive and should be as clean as possible.
These dirty over the years anyway saying more or less - which is also increasingly on the environment.
Why these devices have to be one way or another replaced after a certain time.
Those things are not necessarily tiny - there are smaller and more inconspicuous devices ...
But I do not see constantly at the ceiling, and I am a reliable functionality important as a stylish appearance.
For cost I can only say:
Knappe 100, - Euro (for 4 units) can already be worth a life. Especially when this sum spread over a good 10 years.
Comparable devices with batteries cause considerable follow-up costs through constant exchange of batteries or recharge the batteries. Therefore one must rumklettern all nose long to dismantle the equipment and - once again - to replace the battery. And just to even replace the entire device after a certain time because the sensor optics is slowly blind.
Finally remains only to say:
I hope I never hear the devices except when now and then even conducted test alarm must - and that they really losröhren loudly in case of emergency. :-)