RockJock's optional 4" rear coil springs that are available for use in our Johnny Joint® TJ Wrangler and LJ Unlimited suspension systems are 1/2" taller than our standard spring and are most commonly used in LJ (Unilimited) applications or in heavily loaded TJ applications. These springs may also be used in combination with our CE-9131RH2 spring to address vehicle lean issues. These springs are a dual rate with a combined rate of 79lbs. and a free length of 18.25". Gloss black powder coated finish. If you need help choosing the correct springs for your Jeep - just call the RockJock sales staff!