Coltri Compressors is one of the most important companies worldwide in the design and construction of high-pressure compressors for pure breathing air and technical gases. We started with high-pressure compressors to refill diving cylinders, as used in recreational and military applications. Eventually, we added fire-fighting compressors for ground use, along with industrial gas compressors for nitrogen, argon, helium and Nitrox mixtures for diving equipment, with a maximum oxygen content of 40%. Recently, with the increased proliferation of natural-gas vehicles, we have begun to manufacture compressors to refill the CNG cylinders used in such vehicles.