Ignition Coil Replacement for Mercury Optimax Pro XS efi 4 stroke Engines 30 40 50 60 75 80 90 110 115 125 135 150 175 200 225 250 hp it replaces part number 300-879984T01, 300-8M0077471, 339-879984A1, 339-879984T00, 8M0077471, 879984T01, 879984A1, 300879984T01, 3008M0077471, 339879984A1, 339879984T00, 30-2853, 302853, 556-112, 556112, IGN-1A, IGN-1, IGN1A. Compitable with Sierra marine 18-5158, CDI Electronics 183-0003. APPLICATION: Mercury EFI 4-Stroke Models: 30, 40, 50 and 60 EFI HP Engines Mercury Optimax: 75, 90, 115, 125, 200, 225 and 250 HP Engines Mercury Optimax Pro XS: 115 Pro, 175 Pro, 200 Pro, 225 Pro, 250 Pro HP Engines Mercury Optimax Racing: 225 XS. 225 Sport XS, 250XS, 250 Sport XS, 300XS Mercury EFI 2-Stroke Models: 150(2.5 EFI), 175(2.5 EFI), 200(2.5 EFI), 200(3.0 EFI), 225(3.0 EFI) and 250(3.0 EFI) Mercury Racing EFI 2-Stroke: 225X and 300X PACKAGE INCLUDED: 1 Pack of Ignition Coil 300-879984T01, 300-8M0077471, 339-879984A1, 339-879984T00. NOTE: It is VERY IMPORTANT to check outboard model, serial number, year and horsepower before purchase. Ask us any questions if you are not sure, we are pleasure to help you.