Description Through the modification single chain rings, reduced the transmission system greatly, completely abandoned complex speeds system, reduce the bike weight, looks more compact and simple, and also greatly improve your speed. Features -Color:Black -Material:Aluminium alloy - Size: 13.50X13.50X0.30cm/5.31X5.31X0.12in - Made of advanced aluminum material, durable with strong stability, and not easy to rust. - It can be as a homecoming, Christmas, Thanksgiving or New Year gift to your friends and family. - This item make you no longer worried about the chain dropped, easy to pass through the road. - Narrow wide tooth design increasing the contacting area with the chain greatly, so that each of the teeth can be fully inserted into the chain, increase the grasp force. - The positive and negative tooth design of this bike single tooth chain ring eliminates the need to install a chain guide and does not need to worry about the chain falling off. Made of advanced aluminum material, durable with strong stability, and not easy to rust. It can be as a homecoming, Christmas, Thanksgiving or New Year gift to your friends and family. This item make you no longer worried about the chain dropped, easy to pass through the road. Narrow wide tooth design increasing the contacting area with the chain greatly, so that each of the teeth can be fully inserted into the chain, increase the grasp force. The positive and negative tooth design of this bike single tooth chain ring eliminates the need to install a chain guide and does not need to worry about the chain falling off.