When you order an East Street Racing Radiator, it will not come with everything you need for a plug-n-play install. The radiator cap is not included in the box, and the OEM upper radiator hose will not work with the ESR radiator, so an alternate hose is needed. Also, this alternate hose does not exactly fit right, so it needs to be cut-to-fit. We do that for you in this kit. Also, when you remove the stock radiator, more than likely the rubber grommets that slide over the radiator mounting posts will be dry-rotted and disintegrate when removed from the original radiator. The worst part is if you're working with a 2002-2005 Miata and you go to install the intake tube, it will not fit as the 2002-2005 intake tubes have a resonance chamber on the bottom of them that totally interferes with the radiator! The Spec Miata rules dictate that you can use the OEM intake tube from the 99-00 Miata because it does not have the resonance chamber, so we also provide this as an option.