Aluminum alpha frame linear pull brakes and aluminum rims. Independent Sr front suspension and 20x2.0 bontrager tires and 6 speed Shimano grip shift. Great bike in great condition. A similar used model is presently being sold at source for sports for $250.00 presently.The 2 measurements in the photo show the saddle to floor height range , measure your child,s inseam . As well the dial aluminum 2 position crank gives great figment for the youngest of riders. Bike is in great shape