Accessories:Front Knuckle Arm-2pcsStainless Steel Round Head Screw 3x20-2pcsStainless Steel Collar-2pcsStainless Steel King Pin-4pcs3mm Lock nut -2pcsOriginal Name / Part No:LOS244004+LOS244005Part location:Front knuckle armDoes this product replace a specific part or function?yesProduct major function & usage:Assist steeringMajor advantages of upgrading to this product:1. Aluminum 6061 T6 is light material with high tensile strength for great durability during extreme RC action.2. Delrin collars are inserted to minimize the gap and strengthen the fitting for a smooth and stable drive.3. Precise bearing position minimizes the gap so the rear wheel joints can rotate smoothly, making the wheel more stable.