If you're doing a front-end alignment or replacing a tie rod on your 4WD Ford Super Duty, you'll likely need this adjusting sleeve. This is specifically the FRONT LEFT tie rod adjusting sleeve (sometimes called a coupler) that connects the inner and outer tie rods. It's crucial for setting your toe alignment. It fits 2005-2023 Ford F-250 and F-350 Super Duty trucks with 4-wheel drive, but it does NOT fit models with the 'Wide Track Axle' – so check your truck's specs carefully. It replaces a bunch of common part numbers like ES800977S, 5C3Z3281BA, and many others listed. The sleeve itself is female on both ends and comes with the necessary clamps. This is a heavy-duty steering component, so using a quality replacement like this is key for safety and proper handling on your big truck. TRQ backs it with a 2-year/24,000-mile warranty on the part itself.