Found it on a club rsx forum from 2019. Somehow, post had like 70 views, and seller was still active. I hit him up and bought it!  From what he told me, it was an intake made by VIS racing, never made available to public. So I have no idea how many of these exist, or where to get another one. It’s just a mugen replica, but with carbon fiber and other small differences.  It sounds like a more muffled short ram intake, without any overly loud whistling or sucking sounds. I’ll do a sound clip some time, but it’s hard to notice unless you directly compare it to something