It is a Light Acuity medical unit, not a light & air unit, which are designated utility or scene support units (Tempe FD SS274) in the Phoenix metro area. I've already linked to an article about them. There is also a YouTube video on them, if you look it up.
In the Phoenix metro area, 200 series are East Valley departments for the most part.
Mesa FD 201-229
Sun Lakes 231-239
Guadalupe 241-249
Gilbert 251-259
Superstition (Apache Junction) 261-269
Tempe 271-279
Chandler 281-289
Salt River 291-299
If they run out of numbers, some departments add additional units such as 2201 for Mesa, 2511 for Gilbert, and 2810 for Chandler.
John
Peoria