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 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 TECH SPECS table{border-collapse:collapse;width:100%;} td{text-align:left;padding:8px;font-weight:350;} tr:nth-child(even){background-color:#f2f2f2} th{background-color:#eb212e;color:white;text-align:left;padding:8px;} .desc .specs-heading{font-size:24px;font-weight:600;padding-top:35px;border-top:3px solid #f0f0f0;display:inline-block;border-bottom:4px solid #eb212e;width:142px;margin:0;} Model Black One D-2 Direct Mount Bar Dia. 35.0 or31.8mm Rise 21mm Length 45mm Color Black