The very first oxygen generation system we built was installed in a muffler shop. Today, there are over 1,000 On Site Gas oxygen generators at work in every major muffler chain. The specially priced PRO 4 is designed to handle a shop with up to eight bays. Its ruggedness and durability in the oily environment is well documented. Now and forever, you can end the hassle of wrestling with O₂ cylinders and placing undue stress on your back with an onsite oxygen generator.