The Zipp Service Course SL Stem is a high-quality bicycle stem made of aluminum. It has a clamp diameter of 31.8mm and a length of 100mm. The stem has a glossy black finish and is designed to fit 1 1/8" steerer tubes. It has a +/-17 degree angle, making it suitable for a variety of riding styles. The stem is manufactured by Zipp Speed Weaponry, a well-known brand in the cycling industry.