Quell photoelectric smoke alarm

I moved into a new house in October last year and I thought it didn’t have smoke alarms, so i bought some new ones. Turns out the things I thought were burglar alarms were actually smoke alarms! Doh! So now I have two new unused Quell photoelectric smoke alarms that I don't need, but they have both been removed from their packaging. This auction is for one smoke alarm. This is the type that requires a battery - I have put a new battery in it. All relevant pieces are present including screws and user manual.