The 28 Series is a line of mono-tube shocks and struts specifically designed for competition purposes, featuring individual external adjustments for compression and rebound forces. It has earned an impressive worldwide resume ranging from premier series like Formula 1, Champ Car, Indy Racing League, Formula 3, British and German Touring Cars, etc. down to amateur championships including the SCCA and NASA. The 28 Series has garnered victories at the world's most prestigious races including the Indy 500, LeMans 24 hour, Sebring 12 hour and others. The 28 Series is the shock of choice of racing manufacturers including Dallara, and leading teams including Pro-drive. The 28 series uses an advanced adjustment cartridge that controls the opening and closing of valve loaded ports. Distinct stops (clicks) assure that each port can only be either open or closed. Thus total repeatability of performance is engineered into the damper.