To use this AJA HD5DA amplifier/repeater, first connect it to your HD/SD - SDI source. Remember, since it doesn't have a power supply, you'll need to use your own compatible one. When connecting, make sure the cables are properly plugged in to avoid signal loss. For maintenance, keep it in a cool and dry place. Clean the connectors gently with a soft cloth every few months to ensure good signal transmission. Avoid exposing it to extreme temperatures or moisture as this can damage the device.