Revolution Gear and Axle Discovery Series D44, 4340 Chromoly Front Axle Kit for 2007-18 Jeep Wrangler JK Rubicon, 30 spline kit ONLY works with factory locker. Revolution Gear Discovery Jeep Front Axle Kits 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 large 1350 Style U-Joint. Using the substantially larger inch1350 inch Style U-Joint provides substantial strength increase. All Discovery Axles are backed by a 10 year warranty against failures, including but not limited to U-Joint failure.