XJ Cherokee Boomerang Leaf Spring Shackles 5in Incl. Urethane Bushings and Hardware RockJock 4x4JKS Greasable Heavy Duty Boomerang Rear Shackles for XJ Cherokees and MJ Comanches have been a staple of the off roading and desert racing world for decades! Boomerang shackles, due to their unique shape, allow the leaf spring eye to travel dramatically farther up and around the back of the vehicle in extreme articulation conditions, resulting in full compression and extension of the leaf springs. No matter the type of off roading you are doing, your