Looking for a better feel on the race track? The Silver Series Bulb Gas Shock is designed for reduced gas pressure gain. The robust sealing system and 1/2” (12.7 mm) Ultra strong DURox chrome shaft creates a 36% reduction in rod force and pressure gain compared to the 5/8” shaft shocks. These shocks are owner serviceable, or you can take them to any AFCO shock tuning center for convenient and fast turnaround. With a number of customizable options, you can tailor your Silver Series Shock for any Modified application. How to read and specify your part number: The first two digits are the shock series (example: 75), the third digit is the stroke length (example: 7), the fourth digit is the compression range (example: 3), the final digit is the rebound range (example: 3). Questions? Contact us at 800-632-2320.