Looks like an economy version of my Arrow header.
Why do you "say" that?
I have the Arrow headers, and I was not that impressed.
The Arrow headers are slip fit + springs in the flangs/sleeves bolted to the top/exhaust ports.
I prefere the OEM and this (Black Widow) headers that are *bolted* tight to the top/exhaust ports.
This will require much less tolerance in design opposed to sleeves/springs that allow some more adjustments,
BUT, the sleeve/spring "fit" might induce some leaks although I have not had problems with my Arrows (nor Akra with similar design).
I see that Black Widow skips the tubes between header pipes which I think is good, due to no risk of leaks in this area either.
The effects on engine output is negligible, if there are any benefits at all with this design, even if the OEM also have these tubes between the header pipes.
But on the OEM they are welded=no risk of leaks.
And I see the Black Widow system have the same diameter on the end of the intermediate tube.
The Arrow have a bigger diameter which not all aftermarket can/link tube fits (Akrapovic end can does).
The thick gasket is supposed to sit between the intermediate tube (from headers) and the link pipe from the can.
I had to expand this link pipe to make my Mivv can+link pipe fit to the Arrow header/pipe.
It would be nice if both Arrow and Black Widow presented dyno-figures before/after their systems.