MIP 17110 Heavy Duty Driveline Kit for Traxxas TRX-4 DefenderMIP 17110 Heavy Duty Driveline Kit for Traxxas TRX 4 Defender Heavy Duty Driveline features a scaled look and light weight construction, nearly 30% lighter and 25% slimmer. Ultra strong spline technology and CVD makeup. The HD Driveline has an impressive 35 degrees of articulation and features phased aligned joints that key the male and female splines for smooth power transfer under load with no binding or vibration. All components are heat treated