This flat U bolt kit fits Mack trucks and is sold as a 2-pack, with each kit containing a flat U bolt, two washers, and two nuts to clamp the leaf spring assembly to the axle housing. It is designed to secure the spring and help keep the axle from shifting under load.Interchanges:6QK3123P27QK3131AP2Mack 7QK3154P5This unit is sold in packs of 2.FeaturesSold as a 2-piece pack (kit x2)Each kit includes flat U bolt, 2 washers, and 2 nutsWasher part number FWA-0180Nut part number FNU-4719U bolt component part number FUB-4772-001Tech SpecsKit contents: 1x flat U bolt (FUB-4772-001), 2x washer (FWA-0180), 2x nut (FNU-4719)Sell pack: 2 pieces