The Jeep Wrangler JL 2018-2023 Rear Spring Spacers, Set of 4, 3mm Height Each, are aftermarket components designed to lift the rear suspension of the vehicle. These spacers fit between the coil springs and the chassis, providing a 3mm increase in ride height per spacer. They are typically used to level the vehicle or to accommodate larger tires, enhancing ground clearance and allowing for more aggressive off-road driving. Installation is straightforward, making them a popular choice among Jeep enthusiasts seeking a cost-effective way to customize their Wrangler's performance and appearance.