When I was working in the area last winter, I noticed this unusual fire alarm at 7th Avenue and West 19th Street in Chelsea. Most fire alarms are either mounted on their own dedicated stanchions with unique designs, such as the older ones with the torch (that looks like an ice cream cone) at the apex, that first appeared in the 1910s; a more tame rectangular base from the 1950s; or mounted individually on lampposts or telephone poles.
This one is mounted in a cylindrical post that usually holds “don’t walk” signals or stoplights. Also, uniquely, the pole itself was painted red. When I last saw it the paint job was brand new, but it looks like that metal doesn’t hold the paint very well, as it has been chipping off ever since.