Arms eliminate upper ball joint w/ super strong 1'' ID Stainless American Uniball - Additional caster is built into Arms for greater align ability to help with problematic leveling kit alignments - Allows for increased wheel travel when used with Dirt Logic 2.5 Coilover Resi shocks - Chromoly tubing reduces flex found in stock arms for more positive road feel - 17-4 Stainless Steel Heat treated Uniball pin fits into factory ball joint taper without modification to the spindle for easy return to stock feature - Arms are direct replacements for factory arms on suspensions that require additional strength and align ability. Material Construction Specs - Built with same materials as found on Trophy Trucks - .120'' Wall 4130 Chromoly Tubing. 1.50'' OD. - .250'' wall DOM Bushing Barrels - 1'' ID Stainless Steel American Uniball - 17-4 Stainless Misalignments - 17-4 Stainless Steel Heat Treated Tapered Uniball Pins. NOTE- Before ordering visually check your vehicle's factory suspension for aluminum or steel version. This system will only fit factory aluminum suspension vehicles.