I30N (Veloster N) is just the ball joints.
ES/EGTS/VT2/N Line and hardware kit. These vehicles require hardware kit for these ball joints to work.
FRONT ROLL CENTER/BUMP STEER - CORRECTION KIT (ELANTRA GT/ VELOSTER/ I30N) WORKS WITH THE FOLLOWING VEHICLES. Kona Iron Man Edition - Elantra Sport
A must for lowered vehicles, Whiteline roll centre and bump steer correction kit, is designed to correct roll-centre geometry using specially engineered ball-joints. Raising the front roll-centre results in a substantial increase to front roll resistance and a significant reduction in suspension compression on the outside front tyre during cornering. The result is more even weight distribution and improved tyre contact ultimately improving front end grip, cornering speeds and tyre life when driving the vehicle to it’s potential.