The DIAMETER is 7.25, its 2.80 vertically compressed, 12.00 Extended. Springs and air Bags are ISO & TUV approved. Unlike Others, they are built specifically for Automotive Suspensions, rather than machine and industrial applications. DeNominator-II Air Spring Diameter 7.25 Closed 2.8 Extended 12.00 3049lbs per bag 600psi rated.FREE SET OF 4 1/2 NPT TO 3/8 FEMALE FITTINGS. The item "Set of 4 2800lb DeNominator-II Air Bags 1/2 Port Air Bag (HEAVY APPLICATIONS)" is in sale since Wednesday, May 25, 2016. This item is in the category "eBay Motors\Parts & Accessories\Car & Truck Parts\Suspension & Steering\Lower Kits & Parts". The seller is "bro-speed" and is located in Corona, California. This item can be shipped worldwide.