K2-Circuit 12-13 Civic Si / 12-15 Base Civic (9th Gen)Applications: 12 15 Civic Base (Non Si) 12 13 Si Only Spring Rate: F 14K R 12K Valve: K2 Race Valve This is our standard linear valve. Damper will get stiffer as the strut travels through its range of motion. This can give some harshness with very aggressive curbs. K2 DS1 Valve This is our hybrid valve. We took some characteristics from the Race Valve and our Digressive Valve to give a good mix of both. The damper is a great option for someone driving