XIANQI QUALITY MATERIAL: The bike chainring is made of carbon steel material, which is wearable, resistant to deform and high strength FINE WORKMANSHIP: Precision machining and anodic oxidation electroplating, which keeps smooth surface, bright color which will not faded, good corrosion resistance ability ERGONOMIC DESIGN: The single chainring with ergonomic round shape utilizes the stampede acting efficiently to create more stampede traction, reduce the load and fatigue of the leg or knee and ensure smooth cycling UNIQUE TEETH DESIGN: The narrow wide teeth design increases the contact area with chain, which can enhance the grasp force and reduce the chain drop to allow you to pass through the bumpy road easily EXCELLENT PERFORMANCE: Compatible with bike crank whose BCD is 104mm and chain wheel is 9 speed. Proper thickness ensures no flexing and ultimate chain retention Product Quantity: 1 Piece Product color: black Product size: 64mm aperture; 93mm long