Tokico D-Spec complete strut and shock kit, 1999-2004 Mustang Cobra, IRS The Tokico D-Spec (Damping Specific) series struts and shocks have a sophisticated piston and valving design that provides an extremely wide range of adjustment, far surpassing the range of the Tokico Illumina series struts and shocks. The large adjustment range makes the D-Spec struts and shocks a multi-use damper that can be used for virtually any style of driving. The Mustang D-Specs are suitable for street-driven cars, autocrossing, drag racing, and road racing. The D-Spec dampers have a unique variable-aperture bypass that is controlled by a single adjustment knob. Easily accessed at the top of each strut and shock, the knob changes both rebound and compression damping simultaneously. These D-Spec dampers are sold as full sets (two struts and two shocks). Each set includes an instruction manual offering pointers about how to adjust them.