Those are old school. Back in the old days of EFI Renegade, which was a fuel injection class in the new defunct FFW racing circuit, you weren't allowed to do any tuning to your computer. The only thing you were allowed to do was install that specific box from Motorsport to extend your rev limiter. It also did some A/F adjustment. It had to be that box with that specific Ford part number on it. I remember that box costing about $350 at the time; mid to late 90s. The EFI Renegade has allowed computer tuning for a really long time now, which makes that box completely obsolete. I doubt they still make that box, since it is much better and easier to tune your computer with a piggy back chip. You could hold on to it for Nostalgia sake, or just chuck it.
Kurt