DescriptionThrough the modification single chain rings, reduced the transmission system greatly, completely abandoned the complex variable speeds system, reduce the bike weight at least 1kg, looks more compact and simple, and also greatly improve your speed.Features- Material: Aluminum Alloy. - Size: About 15.50X15.50X0.20cm/6.09X6.09X0.08inch. - 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 bumpy 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.