What type of smoke alarm is this? Is it even a smoke alarm?

Imgur: The magic of the Internet

My house was built in 1998. There are three smoke detectors(?) in the master bedroom, bathroom, and office. My home already has smoke detectors in all the required areas, but I don’t know what these smoke detectors are, if they even are smoke detectors. Thanks in advance

Could be a CO alarm. I don’t recognize it but you can always pop it off the ceiling and take a picture of the back, there’s probably a model number and other info on there that will help us out. It’s definitely either a smoke or CO.