Premium stem with wide clamp width for maximum stiffness- Available shim provides fitment for 31.8mm bars, and when removed, allows use of 35mm bars- Intelligent no-gap clamp design in the bottom ensures no pinch points, and provides equal clamping force for safety and stability- The stem has been certified to the E-Safety Level with Category 5 (Maximum) and passed the EFBE E-MTB Tri Test (EPAC MTB-GR)- Aluminum 6061 T6- 137g including shims