This is a replacement Outdrive for the Pro-Spline HD Axle Kit for the E-REVO® & SUMMIT®. Do you need a replacement Outdrive for your E-REVO® & SUMMIT® Pro-Spline HD Axle Kit? This is it! Made from Hardened Black Oxide coated Steel the Pro-Spline HD Outdrive is designed to handle some serious power! This includes 1 replacement Outdrive.