Is it called Staintune because it's stained black?
The pipes on that look about the same length by eye, so it should retain the lumpy beat of an L twin. I notice that someone has taken some trouble to try and get rid of some manifold heat too, with the serrated retainers, unlike that supposedly Ti item posted recently.
The seller says he thinks it will fit Monsters too, but alas I'm sure he's wrong as the swinging arms differ where they are cross braced and the rear pipe clashes if you try and swap Monster and SS systems. Good design though.
If you're thinking of having a go yourself Mike (I assume you are?) You could do worse than starting with a Monster system and some bends from here >
https://www.everyexhaustpart.com/car...nds-and-elbows