I don't think this is a genuine Evercool EC4010M12ER fan, the seller just put a sticker that looks like it is. The genuine fans are out of production, so I'm not surprised they did this. However, it mostly works with my Synology DS411+ without tripping the CPU fan alarm. I do get the occasional message "CPU fan 1 on DiskStation0 has been resumed", but that is way better than an audible alarm. And it is quiet.