Bought and installed in 2002.Nach now 12 years of service, I have this smoke detector replaced by new ones. Property me again the same buy and hope that they do not cause problems to me. I have every 1.5 years, the battery changed, although an optical signal sounds, replace battery. In the 12 years he has raised 2 x alarm (wood stove) and has after the smoke was gone, stopped saying beeping. Some detectors have no provision, as the battery must be removed. An optical power indicator've got all the smoke detectors. For me it is important that it works and replace the battery every 1.5 years in my opinion, okay. A smoke detector, with a battery that will hold 10 years I find not so good, because the detector is once mounted and then fall into oblivion. Who looks at the ceiling in the hallway and pays attention to the visual display, not a man. Only when the going gets tough, then rush is announced. Warning, this detector is not suitable for the kitchen, there must go a heat detector, otherwise there will be false alarms. From me 5 stars,
