This semi-round U-bolt kit fits Mack leaf spring axle applications and is sold as a 2-piece pack. Each kit includes the U-bolt, two U-bolt nuts, and two washers, clamping around the axle tube to keep the housing secured to the spring pack. It is built as a replacement for the listed Mack application.Interchanges:Mack 7QK3164FUB-4889This unit is sold in packs of 2.FeaturesSemi-round U-bolt design for leaf spring axle mountingSold as a 2-piece sell packKit includes U-bolt (FUB-4889-001), two U-bolt nuts (FNU-4803), and two washers (FWA-0398)U-bolt nut (OEM 21AX781)Washer (OEM 35AX1503)Tech SpecsSell pack: 2 pieceKit contents: FUB-4889-001 U-Bolt (x1), FNU-4803 U-Bolt Nut (x2), FWA-0398 Washer (x2)Nut: Mack 21AX781, Washer: Mack 35AX1503