The 58900-1 Hendrickson backbone is a genuine Hendrickson suspension part. A backbone is a structural suspension component built for medium and heavy-duty commercial trucks, and it forms part of the steering knuckle assembly on a steerable axle.Hendrickson builds suspensions for commercial transportation, and this backbone is sold by Pro Gear and Transmission as a genuine Hendrickson part. Because backbones are specific to the suspension they were built for, call us to confirm proper fit for your application before you order.FeaturesGenuine Hendrickson partBackbone suspension componentStructural part of a steerable axle knuckle assemblyBuilt for medium and heavy-duty commercial trucks