***Notice: The rear damper on PRO is 45mm longer than COMP. This allows you to run drop knuckles and a higher ride height with more suspension travel. If you try and put PRO coilovers on a stock car, the rear will be higher than stock on the lowest setting. So you can only use the PRO coilover by itself if you add helper springs (sold separately) in the rear. PRO coilovers have many of the best things you have come to expect from our competition coilovers like front and rear pillowball upper mounts, light weight aluminum brackets and full tap independent pre-load and ride-height adjustability. They also have high quality components and a robust damper. Heres what you get with the PRO coilovers that is not offered on the Comp: 1. Super Light 8KG F, 6KG R, Linear Spring: PRO coilovers have more grip for higher powered cars due to the 8 and 6kg/mm Japanese high tensile alloy wire used in the SLL Springs The SLL springs make this pro coilover even lighter than the comp coilovers. 2. Caster Adjustability on the front top mount: Comp. coilovers have camber adjustment, and PRO adds Caster adjustability through the circular mounting hole pattern. With Pro coilovers you can turn the camber slot in any direction to adjust both camber and caster at the same time. Caster adjustability is best done by balancing the caster setting between an aftermarket tension rod and this Pro Coilover top plate the wheel to stay centered in the wheel well. 3. Spherical bearing rear lower mount: Comp coilovers have Bearing uppers and urethane rear lower mounts because they are usually paired with OEM knuckles/links. PRO coilovers add teflon lined spherical bearings in the rear lower mount making them perfectly paired with our all-bearing multilink.