PROFORM s new modular 1-2-3 Series Radiators and Accessories fit together just like they should, nice and easy! Start with this versatile 26 wide core Stage 1 Radiator, part no. 126F000 as the foundation for your cooling system. These aren t just your ordinary single pass radiators, they offer beautifully tig-welded tanks, and a slick profile thanks to PROFORM s unique Four-Corner Design. The Four-Corner Design makes it easy to attach an exact fit Stage 2 Single Fan Shroud, Dual Fan Shroud or Dual Fan Bracket, part nos. 1261S00(single fan shroud), 1262S00(dual fan shroud), or 1262B00(dual fan bracket), because the mounting holes line up, making installation a breeze with the included hardware. For the ultimate professional look at DIY costs, take a 1-2-3 Series Stage 3 Fan or Fans, part nos. 67016 or 67027 for single fan setups, or 67012 or 67013 for dual fans setups; and mount them up to the pre-threaded holes in the shroud or bracket; then top it off with an adjustable fan controller to make life easy. It s easy as 1-2-3! This is a really nice cooling system that's ready for the show, streets, or strip! This Stage 1 Radiator has dual one-inch tubes, single pass, with optimized louver design to maximize cooling, and deep draw headers for an extra solid tube/header seal. Billet aluminum filler neck with overflow tube, and a billet aluminum 16 psi cap are included. No epoxy or anything else like that just tight tolerances all around. Building your custom cooling system is easy!