This high-quality FSA OS-99 CSI stem is a great addition to your road, cyclocross, gravel, racing, or mountain bike. It has a 31.8mm clamp diameter and a 1 1/8 inch steerer tube diameter, making it compatible with a wide range of bikes. The stem is made of carbon material and alloy, which ensures its durability and strength. Its length is 120mm and angle of +/-6 degrees.