This is a front crankshaft oil seal installer for use on Volvo MP7 MP8 D11 & D13. This is a replacement to volvo part # 88800501. This works with Mack seal numbers: 21081526, 21347087, 21779548, 7421347087, 85108423, 7421347087, 21081526, 21347087, 21779548, 7421347087.