1-2-3 Radiators are just like the name implies, EASY! Proform s new line of radiators and modular accessories all fit together just like they should. These aren t just your ordinary single pass radiators, they offer beautifully tig-welded tanks with a slick looking profile design that is unique to Proform. These radiators also incorporate PROFORM s unique Four-Corner design that makes adding a shroud or bracket easy because all the mounting holes line up. All radiators are dual one inch tube, single pass, with optimized louver design to maximize cooling, and deep draw headers for an extra solid tube/header seal. No epoxy or anything else like that just tight tolerances all around. Building your custom cooling s ystem is easy: Stage 1 -start by choosing the radiator that is the right width and inlet/outlet configuration for your vehicle Stage 2- Choose a single fan or dual fan shroud or bracket that fits your radiator Stage 3- Choose the correct fan(s) to match your shroud/bracket. To top it off, throw a fan controller into your package and you've just built yourself a really nice cooling system that's ready for the show, streets, or strip!