Good thick strong wire. I have an electric tiller for my yard and needed a way to get the pier exit 50 feet closer to the tiller. I was amazed, no, amazed that such an incredible invention existed. I no longer have to call an electrician every time I need to be too far from an outlet. I just unwind this magical device and phew, the power is even closer to where it's needed. The end of the fork even glows so I can find it in the dark. The bright yellow color helps me not mow this cord, unlike my poor hose. A green hose in the green grass is a terrible idea. O mankind!