Parallel Four Link Grade Eight Hardware 9/16"-12 x 4" Includes Eight Grade Eight 9/16"-12 x 4" Yellow Zinc Bolts, Eight 9/16"-12 Nylock Nuts, Two Grade Eight 5/8"-11 x 3 1/4" Yellow Zinc Bolts and Two 5/8"-11 Nylock Nuts. This kit is used for our parallel four link suspensions that need a 9/16" bolt and use a suspension joint that has a 2.625" mounting width.