Kit Guarn. Rsu Ac-Opt4000 Micr Genuine Mattei lubricants and parts are engineered with the same durability and value that we put into our air compressors systems. Other air compressor manufacturers often charge a small fortune for genuine parts and oil, which sends you looking for alternative suppliers. Mattei uses a common sense approach. Our parts are reasonably priced to ensure you get top performance at a price you can afford. Get what you pay for with our Genuine Mattei lubricants and performance parts.