Tanabe TDF115 DF210 Lowering Spring with Lowering Height 0.9/1.0 for 2006-2007 Honda Civic SI Coupe and Lowering Height 1.3/1.1 for 2007 Civic Si Sedan All coil springs feature Sustec 210 technology which is a series of manufacturing methods developed to create a stronger, thinner, and lighter spring using high tensile steel Tanabe springs are some of the strongest springs available for automotive use (2100n/m) Tanabe springs carry a comprehensive 3 year warranty and are designed to not sag