Dobinsons 5 degree caster adjustment drop boxes, to drop the fixed end of the front control arms holding the front axle in place to correct for lift heights of 4" or more. Leading arm (front control arm) modifications are not required when fitting this part number, but gaining clearance on the frame to mount these properly is required. These are an alternative to caster correction plates on the axle end, and also an alternative to caster correction bushings. Use of these drop boxes should not be combined with any other form of caster correction. Purchasing this kit will include 1 x LH and 1 x RH side drop box, exactly as the photos show.