Power plug

A power plug, comprising:

• a hollow housing having a wire hole in the end;
• a limitative set received in the hollow housing, wherein a middle inner side of the limitative set extends interiorly to form a loop, a top of the loop defining a first limitative slot, a bottom of the loop defining a second limitative slot;
• at least two slip rings placed into the first limitative slot and the second limitative slot respectively and insulated from each other by the loop located at the middle inner side of the limitative set;
• at least two bases each placed in the first limitative slot and the second limitative spot respectively, revolvingly contacting each slip ring, insulated by the loop located at the limitative set;
• and
• at least two blades mounted in each base and electrically connected to the slip rings;
• wherein a ring rim of each base extends upwardly to form a ring wall, the ring wall defines at least a notch through the lateral of the ring wall, the inside of the ring wall receives a contact piece, the contact piece has a contact lump which is embedded in the notch, the tip of the contact lump bends to form a contact part and extend out of the notch to tightly contact the slip ring by the contact part, each blade which mounted in each base electrically contacts the contact piece.