This is a 12V fixed-voltage MyVolts-branded power supply adaptor designed to meet exactly the power specification of your NUX Mighty 8BT MKII Amp.
The "myVolts 12V power supply for NUX Mighty 8BT MKII Amp" would be an excellent fit for users seeking a reliable and efficient 12V power supply to power their NUX Mighty 8BT MKII Amp.