To use this Line 6 RXS12 receiver, first make sure you have a suitable power supply as it doesn't come with one. Connect it to your Relay G50 or G90 wireless system according to the system's instructions. When using, keep it in a dry and cool place to avoid any potential damage. As for maintenance, just give it a gentle wipe with a soft cloth from time to time. Remember, this unit has only been power - tested, so handle it with care.