Viking's front coilover kit combines a high quality hybrid spring with a 19-position double adjustable shock. The upper coil fits the upper spring perch on your vehicle while the lower part of the coil matches the coilover shock bottom. A coil spring compressor is not required, as the adjuster acts as the compressor. The optional thrust bearing and spanner wrenches allow for easy adjustment of ride height from 1.5" to 3" lowering. The shock itself has independent compression and rebound adjusters to allow custom tuning for various driving conditions. UMI recommends choosing bearing ends for increased reliability and performance, especially for corner carving, drag racing, auto-x, and road race applications. The kit includes two front coilover shocks, double adjustable, and two front springs with a choice of spring rates ranging from 250-550lbs. The spanner wrench tool is used to adjust vehicle height while the shock stays mounted. The thrust bearing kit, recommended for easier adjustments, is designed to be placed between the spring and the spring seat attached to the shock. This kit is not necessary for installation but is recommended for easier adjustments. Front Spring Rate Options: - 250lb: 11” tall springs for drag race only, serious lightening required. - 350lb: Small block cruise or drag race with lightening required. - 450lb: Small block cruise, big block drag race. - 550lb: Small block handling, all big blocks except drag. Overall, Viking's front coilover kit offers adjustable performance features for various driving conditions and applications.