RockJock's greasable Boomerang rear shackles for 1987-1995 Jeep YJ Wrangler vehicles directly replace the stock shackles with our new, heavy duty units. Our shackles feature laser cut, 1/4" thick steel side plates that are a boomerang shape, to allow the spring eye to travel much further around the back of the vehicle for increased articulation. Additional features include Energy Suspension fluted urethane bushings, grade 8 greasable bolts that feature zerk fittings on their heads for greasing of the bushings, and center bolt-in sleeves for added rigidity. Shackles are 4 -3/4" tall from bolt center to bolt center. Finished in corrosion proof gold zinc plating and sold in pairs.