For 1989-2016 Cummins 4BT 3.9L,ISC 8.3L, B Series 5.9L, ISB, ISL 5.9L 6.7L, QSB 5.9L 6.7L. PERFECT DESIGN - For installing front and rear crankshaft seals and wear sleeves without damaging seals and leaks, also removable rear crankshaft seals.