CCI Controls Model 3350 Monoxide Detector

I purchased a used 1997 Safari Serengeti Motor Coach and the flush mount Carbon Monoxide Detector is out of date. I need to replace it but cannot find this particular model. Does anyone know where I could get one or if some other company makes one that would work instead.

The portion that is sunk into the ceiling is 5-5/8" by 2-1/2" and the portion flush to the ceiling is 6-3/8" x 3". It is white but I would be okay with brown or black.

Thank you in advance for any assistance!

happy trails,
Ray Delworth