Reverse E-Black One D-2 Stem (31.8/35.0) 35mm BlackTested and certified for E Bike use according to German EFBE EPAC MTB GR Tri Test which is one of the toughest test procedures in the world One stem fits 2 handlebar diameters Special 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 Aluminum 6061 T6 152g TECH SPECS steerer dia. 1 1 8" bar