Custom made New.
Bigger & smoother flange from pressed steel.
3" pipe is steel.
Designed for maximum flow.
Power gains has been up to 8rwkw midrange (3700-5700rpm) at same boost level (dyno proven).
Has also gain 3 pounds in boost just from the freer flow.
Price $450.
These are generally not available off the shelf. For someone to make one up and put it on would be at least $550.