Let's get one thing out of the way--the OS-99 Road Stem is the lightest stem that FSA makes, and no, the "7050 aluminum body" isn't a typo. By using a proprietary 3D forging technique and special heat treatment ("witchcraft" is the technical name) FSA makes the OS-99 as strong as a heavyweight stem but as light as a part made of pure carbon fiber. To be fair, the faceplate is built partially from carbon, to achieve the perfect balance of strength and weight, and the unbreakable bolts have been forged from titanium, so the OS-99 isn't pure aluminum. The faceplate also has a serrated surface that will grip both carbon and aluminum bars, and a rise of /- six degrees, depending on which way you set it up.