Square Ignition Coil for Cadillac Chevrolet GMC Tahoe Silverado Yukon Sierra Workhorse Fastrack Express Savanna Compatible with 12556893 12558693 12570553 392889925 410002 3859078 38590782 DIRECT REPLACEMENT/ UPGRADE over your original stock coils. We only use the highest grade materials. This makes our product durable and reliable under extreme conditions while providing High Electrical Resistance, strong Spark from plugs, and being resistant to Corrosion and Abrasion IGNITION COIL PACK for, 4.8L 5.3L 6.0L 8.1L, C4500 Topkick, C5500 Topkick, C6500 Topkick, C7500 Topkick, C7500 Kodiak, Silverado 2500 HD, Silverado 3500, Savana 3500, Sierra 1500, Sierra 1500, Sierra 2500 HD, Sierra 3500, Avalanche 2500, Silverado 2500 HD, Silverado 3500, Suburban 2500, Savana 2500, Sierra 1500 HD, Sierra 2500 HD, Sierra 3500, Yukon XL 2500, Escalade, Sierra 2500, Express 3500 IMPORTANT: Please check interchangeable part numbers and/or verify if car year, make, model, sub-model, engine size and VIN number matches before purchasing products. The manufactures of the vehicles changed their coils mid-year so your vehicle might need the ENAIC350808 (Square) or ENAIC121308 (Round) Coils depending on what month the vehicle was made in. Other Interchangeable/Compatible Part Numbers: C1208 D581 5c1083 E226 52-1618 Ic400 12558693 H6t55171zc Uf-271 Lifetime Warranty