The NUX Metal Core Deluxe MKII is a preamp pedal featuring 3 high-gain amp models: Duo Rect, Fireman and VH4:
You can upload your own favourite IRs via the MetalCore editing software. MetalCore will automatically convert the IR file, just make sure your IR file is in WAV format. The Metal Core Deluxe MKII offers you 5 memories in which to load third-party IRs (4-8). It accepts resolutions of 512 samples.
If you don't have a computer, you can edit the pedal's functionality with the EFX Mobile APP. (For iOS, you'll need a Lightning to USB adapter. While some USB Type-C to Type-C may work with Android, using an OTG adapter can ensure that most Android systems will work correctly with the Metal Core Deluxe MKII.
When the pedal is not connected via USB, hold down the pedal while plugging in the power to start the pedal. If the LED indicator flashes GREEN 3 times, the IR is engaged. If the LED indicator flashes RED 3 times, the IR is disengaged.