Revolution Gear and Axle Discovery Series D44, 4340 Chromoly Front Axle Kit for 07-18 Jeep Wrangler JK Rubicon, 30 spline kit ONLY works with factory locker. Kit comes with 2 inner axles, 2 outer stub axles, 2 Dana Spicer 5-7166X U-joints and 8 Full Circle Snap rings to hold it all together. Revolution uses the large1350 style u-joint. Using the substantially larger 1350 u-join provides a substantial strength increase. All Discovery Series Axles are backed by a 10 Year Warranty covering manufacturing defects and axle breakage, bent axles and twisted splines. This warranty is non-transferable. U-Joints are only covered under warranty for 1 Year (Other than Revolution Gear HD Chromoly U-Joints). Parts subject to normal wear are not covered under warranty; this includes bearings and seals.