Natural light anywhere you want light You won't believe the difference skylights make in your home. and even bigger. You get more than your money's worth with Sun-Tek. Our Curb Mounted Polycarbonate Series which includes the CM, CMA and the MDCMA styles are all good choices for a very durable solution for a curb mount application. The CM being the most economical is constructed of impact rated polycarbonate that is 30 times more impact resistant than acrylic. The CMA upgrades the CM with an aluminum trim ring for strength and stylish aesthetics. The MDCMA is the most rugged of the group with a welded and riveted frame featuring a Miami Dade hurricane rating.