The KYB Gas-a-Just monotube shock absorber has additional performance advantages over the twin-tube design: It can instantly, automatically adjust to more handling and control needs and never experiences performance fade due to aeration. The Gas-a-Just is available as an OE Monotube replacement and as an OE Twin-tube performance upgrade. 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. The monotube design provides the best combination when you sometimes need or want more than average or designed ride control performance and steering responsiveness. The KYB Gas-a-Just is a high pressure, Nitrogen gas-charged monotube design that includes every quality component that our global OEM products include.