Spicer blue differential cover. Engineered for off-road. For full-performance differential covers that are engineered with the serious off-roader in mind, and get the same name you trust for all your drivetrain products genuine Spicer. Manufactured from high-strength nodular iron, Spicer performance differential covers are built to meet the demands of any environment. Don't trust a knock-off to protect your intricate differential parts. Count on the legendary Spicer brand.