an electric plug in which novel cable securing means is used for anchoring the cable to the plug so that any pull on the cable will prevent the cable from being pulled free from the plug and will also prevent the three wires in the cable from being accidentally disconnected from their associate electrodes . the electric plug has three electrodes with portions projecting beyond the plug , these portions being hook - shaped and designed to enter three openings in an electric outlet box , the plug being rotatable through an angle for securing the plug to the box .