NPO 法人CATNIP 2 We bought a bunch of these. Most are on proximity switches, and not used much. But two are on overnight, every night: they have lasted 10 months and both died within a few days of each other. (They are indoors, well ventilated, neither hot nor cold). Possibly we have just been unlucky, but if ours are anything to go by, 4000 or so hours is a more likely duration of the LEDs. YMMV of course, but we would be cautious about buying more. That said, they are nice little units - so if you are willing to replace them annually, they may do the job.