Product information updated on 2021-08-25, Manufactured by BellTech - Part Number Belltech 6423, 2011-19 Silverado/Sierra 2500 Pickup, 2015-20 F150 (Ext/Crew Cab short bed) 1 inch Rear Drop Shackle kit, 2011+ Chevrolet Silverado/Sierra 2500 Pickup 1 inch Rear Drop, 2015+ F150 lowering shackles, 1 inch drop. These are the same as 6424 exc they do not include the 1 degree shims. Research says that these will also fit the 2020 to 2021 Silverado/Sierra 2500/3500 trucks but they have not been approved for that application. Use at your own risk., Belltech Shackle and Hanger Kits are designed to lower the rear of your leaf spring equipped Sport Truck or SUV by up to 5” depending on the application. By engineering bracketry or replacement components (Belltech Shackle and Hangers) to reposition the front and/or rear leaf spring mounting points (spring eyes) you can simply and effectively lower your leaf spring equipped Sport Truck or SUV without changing the factory leaf spring. This allows you to retain OEM ride quality and possibly more importantly factory load capacity. At Belltech, we offer both Belltech Shackles and Hangers as individual components as well as complete kits depending on your lowering requirements.