Yes dude, thats a series 1 Mugen.
The same that I had.
I can't speak highly enough of this system. Granted it was the only system I had on my S2000 in 3 years but it was probably the best part of my car.
Being JASMA rated it has minimal drone.
It's hard to say if it's over intrusive really as the S2000 has no roof, so it's hard to compare but I'll say it's very good to live live, fine on motorways.
Open it up and it starts to sing a mighty fine tune - loved the S2000 at 9200rpm.
Towards the end of my time with the S2000 I moved to a de-CAT and a Mugen manifold and even then it still performed great, with no drone and sounded great.
IIRC my noise test at Spa read 82BD's so it's pretty quite in the grand scheme of S2000 systems.
If I was to go again, this would be first choice, if it was around, as even back a few years these were hard to get hold of, so now, probably even more so.
GET IT.