Thru axle converter TC-12/15 , it is made of light-weight, high-strength 7075 aluminum alloy, precision-machined by CNC, safe and reliable, stiff and durable. Front Bicycle Hub 15x100mm to 12x100mm Adapter Converter ,15mm Axis to 12mm, fit Disc Road Bike ,MTB 15x110mm to 12x110mm, 20x110mm To 15x110mm