After many years of testing and development we are pleased to offer these stainless headers. Constructed out of the highest grade 321 stainless steel. A material much more suitable to high exhaust temperatures such as those produced from rotary engines. Each one is painstakingly TIG welded together for best appearance and strength. The length and collector have been optimized to provide the most power for a n/a rotary using a stock or modified intake system. This is the same design that made 428 rear wheel horsepower on our personal n/a 20b Rx7. That is over 500 horsepower at the flywheel!