All Weather Fluid: Contains special modifiers to reduce friction and ensure smooth rod reactionFull Displaced Valving: Valving automatically adjusts to road extremes to provide consistency and ride comfort1-3/8" Bore: Larger bore than most shocks to provide more efficient and consistent controlFluon Banded Piston: Works with the existing groove tube technology to provide responsiveness to changing road conditionsUnique Groove Tube - PSD: Precision tapered grooves in the pressure tube perform like an additional stage of valving for optimum light truck ride tuningThe Monroe Sensa-Trac truck shock absorber with PSD (position sensitive damping) and the Safe Tech system combines our exclusive precision tapered grooves in the pressure tube with application engineered valving and Fluon banded piston to improve the ride, handling, and safety characteristics of the vehicle. These features allow the Monroe Sensa-Trac truck shock absorber to adjust more rapidly to changing road and weight conditions than any other available shock absorber. The result: enhanced control with uncompromised ride comfort.