Using this power supply test line is easy. First, connect the two banana plugs on each connector to your power supply or multimeter. Then, depending on your needs, choose from the three options on the other end: alligator clips, mini - grabbers, or the USB A jack. For example, if you're working with a circuit board, the alligator clips can hold onto components easily. When using the USB A jack, remember the yellow and green wires are for power pins only. As for the limitations, this test line isn't rated for temperature, voltage, or current. So, make sure to use it with a maximum of 12VDC and 2 Amps to avoid any damage. In terms of maintenance, keep it clean and dry. If the wires get dirty, you can gently wipe them with a dry cloth. And if the confusing yellow and green wires bother you, you can cut them off just like we did at home.