This is a set of optional ST Racing Concepts Blue Oversized Front Knuckles with Bearings. Using high quality CNC machined aluminum, these oversized Aluminum Front Steering Knuckles greatly increase the strength of your front suspension, while adding great looks to your Traxxas electric Stampede, Rustler and Slash, as well as the Nitro Slash. Because of the increase in size of bearing for durability, we have included a full set of 5x11mm ball bearings (replacing the stock 5x9mm bushing) for improved efficiency of the rotating axle and durability.