2015 Dana 21060S, School Bus, Axles, Complete Rears, Fits to: Blue Bird BB Conventional, (Used) 2015 Blue Bird BB Conventional, COMPLETE REAR DIFFERENTIAL- Part Number: 511223, Serial Number: HN04545187, Make: Spicer, Model: 21060S, Ratio: 5.29, Capacity: 19,000 Lbs, Hub Bolts: 10, Brake Type: Disc, For more information about this item, give us a call. We ship Worldwide! (CRG HEAVY TRUCK PARTS) 929 W PULASKI HWY ELKTON, MD 21921, Ratio 5.29, Serial# HN04545187, Casting# HN04545187 1BAKFCPH2FF314060