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 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 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 correct, monotubedesigned OEM replacement shock Specifically calibrated to help restore the original handling and control characteristics of your Hyundai High gas pressure design provides instant, extra control monotube design outperforms all other standard shock absorbers Unique, airfree, hydraulic unit eliminates performance fade