N-tercooler ring is 20 in. For supercharged or turbo applications where nitrous is not an option, Nitrous Express offers these N-tercooler systems as an alternative.These systems spray nitrous over an air-to-air intercooler, reducing air inlet temperatures dramatically. For example, in a dyno test, a turbocharged Honda® equipped with a Nitrous Express N-tercooler increased its baseline by an astounding 52 hp! The item "NX N-TERCOOLER SYSTEM 5LB BOTTLE #20000-05" is in sale since Monday, May 28, 2012. This item is in the category "eBay Motors\Parts & Accessories\Car & Truck Parts\Turbos, Nitrous, Superchargers\Superchargers & Parts". The seller is "pwrparts" and is located in Mauldin, South Carolina. This item can be shipped worldwide.