1978 Mack 11KHA, Truck Trailer, Tandem Cutoffs, Fits to: Mack RD685S, (Used) 1978 Mack RD685S, COMPLETE TANDEM CUTOFF- Part Number: 64KH595P4, 64KH595P1, Serial Number: 5236DP , 4207AP, Make: Mack, Model: 11KHA, Ratio: 4.17, Capacity: 21,000Lbs, Hub Bolts: 5, Brake Type: Drum, 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 4.17, Serial# 5236DP , 4207AP, Casting# 5236DP, 4207AP RD685S3685