The number likely refers to:

: Download a zip package containing the Checkra1n 0.12.4 ISO file and the Create Bootable Media

If you’ve spent any time in the iOS jailbreaking community, you know the name . It’s the gold standard for semi-tethered jailbreaks, leveraging the unpatchable checkm8 hardware exploit. However, there has always been a catch: Checkra1n was built for macOS and Linux, leaving Windows users in the dark.