Made by Nicot and distributed by Orion, the RXB has a very KTM "inspired" frame design with a Honda CB derived single cylinder 249cc engine. A lot of Chinese drop-shipped bikes are advertised as "250" cc, but this one actually is. It's got six gears, too. Capable of 20-ish horsepower, lightweight, simple, cheap, it's about 75% of a KLX250 or CRF250L for 25% of the price. Mine is one revision older than the one they're selling now -- the current version has fuel injection. Mine is a carb.
Somehow, my local DMV tried to give me shit for the relatively tame Shinko 805's on my KLR, but this thing and its tires sailed right through and they let me slap a plate on it. Go figure. (The stock ones it came with weren't even DOT. I replaced the rear with a Tusk DSport after burning it up pretty much immediately.)
It really kind of isn't. It does have packing, but it's otherwise pretty straight through. I had to take it apart (this required some cutting) to put a spark arrestor in it to make it legal for use in the state forests around here. While I was at it I put a gimcrack homebrew baffle in it which made it a little better, but it's still not exactly silent.
The problem is, finding an aftermarket one that's quieter is a case of trial and error because all of the aftermarket options seem to be equally obnoxious, aimed at the MaD pErFoRmAnCe GaInZ, Yo!!!!1!! crowd. I'm thinking at some point I will stumble across a stock silencer from a similar displacement bike and chop it off, then do some adapting work. It's low on the list of priorities.
Relatedly, if anyone has a pair of stock pipes for a Shadow ACE 750 (2000-2002, I think) I'll buy or happily trade you the pair of loud as shit Vance & Hines pipes that came with my bike.
Hell yeah, OP. Respect.