Compatible with Dualtron X, X2, X LTD, Sonic Alien, Storm, and Thunder 3, this 40x52x7 headset bearing is a steering component used in the stem headset assembly. It is a precision steel bearing with sealed races, designed to support smooth steering rotation under load. The bearing presses into the headset cup and interfaces between the steering tube and frame, allowing controlled movement while carrying axial and radial forces. Installed during headset assembly or service, it restores accurate steering feel, alignment, and long-term durability. Supplied as one bearing.