These are the steer arms commonly found on the bottom king pin on an Axletech 4000. The tie rod attaches to them, tying the 2 steering knuckle together. The lower arms from a wide version Axletech will fit on a narrow Axletech Axle, but the narrow Axletech steer arms will not fit on a wide Axletech. There's a pocket in the wide steer arm that is required for the updated king pin on a wide Axletech.