We've all been there... you need just a little bit more slack in the cord and give it a pull only to have it disconnect 100 feet away. Most of us have been just tying the cord into a knot like the photo above illustrates, but, by doing this you are putting stress on the cord. What's the solution? Prime Wire Locking and Lighted Cords.
The integrated locking mechanism clamps down hard on the other cord and doesn't let go saving your cord from being contorted and possibly prematurely ending its life. Some models are also feature an indicator light that quickly lets you know if you have power saving you from running back to the source should you have a problem.