KYB 17-20 Ford F-250 4WD / 17-22 F-350 4WD (Exc. Cab & Chassis) Gas-a-Just Gas Shock - Rear - 5540018

The KYB Gas-a-just monotube shock absorber has additional performance advantages over the traditional twin-tube design: It can instantly, automatically adjust to your performance needs and never experiences fade due to aeration. The KYB Gas-a-just has two separate working chambers: An air-free hydraulic piston and valve area for responsiveness and control, and a second high-pressure nitrogen gas area with a floating piston that provides a comfortable ride during normal driving and adds instant performance on demand.