Take the time to properly rebuild your ISOs. Respect the USB 1.1 bottleneck. Enable that linked mode. And then enjoy your PS2 library without ever hearing the dreaded grinding noise of a failing DVD drive again.
It looks like you’re referencing a specific tool——likely related to playing PlayStation 2 games via USB storage (external hard drive or flash drive) using OPL (Open PlayStation 2 Loader). usbutil v21 ultimate for ps2 usb mode 2 link
It could be a typo, misremembered version number, or a repack from a forum (PSX-Place, PS2-Home, etc.) with: Take the time to properly rebuild your ISOs