Tokico DE3753 D-Spec Rear Shock for Mustang Twin valves help provide precise damping, helping reduce the roll rate for more secure handling even at softer settings A special oil seal design for the piston enhances the dynamic response of the suspension throughout the range of adjustment Damping force adjustments alter both the rebound and compression damping rates simultaneously, for consistent control. Turning the knob clockwise increases firmness; counterclockwise adjustments soften the settings. Each shock or strut application has its own specific damping curve shape and range, precisely tailored to the vehicle