There are probably tens of thousands of Ingersoll Rand P185 tow behind air compressors in use and for sale around the world. I have not been able to get any specific information on this venerable compressor from IR, except that it’s a portable – being that it’s a towed air compressor – and that it’s supposed to provide 185 CFM of air flow when running optimally.
It appears as though Ingersoll Rand is no longer selling portable construction compressors, preferring to manufacture and sell construction equipment like jackhammers and what not as well as industrial air compressors.