CNC high-strength aluminum. Increase the corners and high-speed stability for your mini bike. Damper has an Active/Speed-Sensitive Damping System and adjustable dial. Lightweight aircraft-grade aluminum with 7 different anodized surfaces to choose from. Unit measures 10″ total and has 2.75″ worth of movement up and down the shaft. The ball joints have a 0.315″ (8mm) opening.