Zipp Speed Weaponry Service Course SL Stem - 70mm, 31.8 Clamp, +/-17, 1 1/8", Aluminum, Matte Black, B2The Zipp Service Course SL Stem, crafted from 7075 aluminum, features a shape thats strong and lightweight, resulting in a 1. 85 grams per newton meter of stiffness. That results in no flex sprints and accelerations. Forged AL 7075 Machined and relieved faceplate Features titanium hardware with TORX heads on all bolts for precision torque readings and ease of adjustment Product Specifics Stem Angle (deg): +17 Stem Angle (deg): 17 S. H. I. S. Stem