The package arrived well and securely packed in us and to the surprise of even 4 Longlife 9V spare batteries were included, the other the 4 smoke detector incl. Battery and each 2 screws and 2 plugs for attachment and an easy to use manual.
We fastened the smoke detector with the supplied screws with us on the beams of the visible roof truss and hence need the plugs not that one but even so can always use good.
Here we just easily twisted off the battery compartment cover and remove and use these as a "template" for marking the screw. Then we unpacked the battery and plugged into the contacts and turned the smoke detector back on the battery cover already attached.
With the small dimensions of 101 x 34 mm and the pleasant white to creamy color these smoke detectors work quite small and fit very well in the room look and do not disturb.
According to the manufacturer to keep the supplied batteries for approximately 1 year. If the batteries are weak, the smoke detector is in short intervals a faint signal from what we had also tested successfully by the present old battery. This is the sign to change the batteries.
The supplied spare batteries according to the manufacturer to have a lifespan of up to 10 years.
Thus the whole system is also effective in use, and operational readiness is guaranteed, is to be carried out at least once a week a functional test. For this purpose, only the alarm button for about 5 seconds to press and it will sound a piercing alarm. It sounds, the device is still ready for use.
All in all you get here an excellent price-performance ratio and has a sense of security.