King Shocks 3.75 ID Coil Springs 20 x 400lb

King coil springs have closed and ground ends to sit flat and deflect true. These coil springs are specifically wound for off-road applications, not repackaged car springs. The spring rates, wire diameters, and coil lengths have been developed through extensive real-world testing on all types of terrain. King Shocks race winning designs have been put to the test in the heat of battle from Baja to Dakar. King Shocks has the largest selection of springs to match your application. Decoding King coil part numbers example: SPR375-22-250: 375 = 3.75 internal diameter spring * fits 3.0 shock; 22 = 22 inches long; 250 = 250 lbs. spring rate. The spring rate is a number that represents the amount of force in pounds that it takes to compress the coil 1 inch. King shocks are available with many coil spring options depending on your application. A single rate spring is a single coil on the shock. As the coil compresses the rate increases at a linear rate. If the spring rate for that coil is 300lbs per inch then compressing that coil one inch generates 300lbs., two inches generates 600lbs., 3 inches equals 900lbs.