This is the kernel or software files for the R4i 3D Revolution for DS from ndsill.net that is no longer supported.
Can run almost any DS Game and DS Homebrew.
I went to auction at a mom/pops video game store few months ago that was closing, and bought 11 slims for $200, 1 was DOA but 10 work fine. so hella deal. Already rgh3'ed 8 of them. But most younger kids don't even want anymore, unless it plays stupid "fortnight", or newer shit.