APM's narrow, wide tooth bicycle cranks take statistics hardness, electrical conductivity, and crystal as standard to reinforce the strength on integrated forging 7050 crank arm and imported European aluminum 7075 100% CNC chainrings for highest performance, with 6 points index shifting up the design of the chainrings will provide faster, smoother and precisely shifting transfer of your bike and make you take the lead. The unique design of a lower pressure angle reduces the load of chainrings, makes the transmission better, increases the chain’s life, and enlarges the width of the bottom curve for adapting changes of different chain distances and increasing 15% transmission efficiency.