Seem's a bit risky but if you have 2.5 go for it, but remember it cannot brick the PSP because of Sony's security and if it does, we can make it into a downgrader since it would access the flash. Don't hold me accountable for what happens your PSP's though, I'm just saying if you've got a 2.5 PSP and are brave/have warranty, should test it. Or someone with enough knowledge can look into the file to see if it would work.