Easy Installation: The precisely machined wheel spacers feature an intuitive design and clear instructions for simple and quick installation. Each pair of wheel spacers comes with a user manual, detailing the specific installation steps. Note: Do not use an impact wrench; it is recommended to use a manual wrench. Forged Aluminum Alloy: The spacers are forged from 6061-T6 aluminum alloy, providing exceptional strength and wear resistance, making them more robust and durable. The surface has a Dacromet coating for oxidation resistance and heat treatment, ensuring high precision and stability while enhancing hardness and corrosion resistance. All spacers come with grade 10.9 bolts. Wide Compatibility: These wheel spacers are compatible with many Jeep vehicles from 1972 to 2010, including: Jeep: 2008-2019 Journey, 2007-2018 WRANGLER JK JKU (NOT FOR 2018-2019 JL), 2005-2010 Grand Cherokee WK, 2005-2010 Commander XK, 1972-1978 Marquis, 1999-2004 Grand Cherokee WJ (NOT FIT 2011-2017 Grand Cherokee WK, TJ YJ ZJ). Product Specifications: Our wheel adapters includes 4 wheel spacers, each with a thickness of 1.5 inches (38.1mm), a bolt pattern of 5x5.5 inches, a hub bore of 2.81'' (71.5mm), and a thread pitch of M1/2-20. Please carefully check your vehicle's manual specifications before purchasing to ensure compatibility. Enhanced Driving Safety: These wheel spacers increase the axle track by 1.5 inch, widening the wheel track to lower the vehicle's center of gravity. This effectively solves severe body sway during high-speed cornering, significantly improving the vehicle's grip, stability, and handling.