a housing having one side provided with at least one engaging fastener, the engaging fastener further comprising:

a sliding hook slightly projected from the side of the housing;

a connecting portion connected between one end of the sliding hook and the housing;

a rib formed on an inner surface of the sliding hook adjacent to the connecting portion, the rib extended along the sliding hook about a predetermined length; and

a positioning recess formed on an upper surface of the sliding hook adjacent to the connecting portion; and

a hanging base having a connecting side and a mounting side, the connecting side provided with at least one engaging recess, the engaging recess comprising:

an inserting portion formed with an elastically positioning piece and a positioning projection on the elastically positioning piece, the inserting portion being aligned with the sliding hook of the engaging fastener for receiving the sliding hook; and

a sliding portion having a slide track corresponding to the rib of the engaging fastener;

wherein when the sliding hook of the engaging fastener inserts into the inserting portion, the sliding hook slightly biases the positioning projection on the elastically positioning piece to generate an elastic bias while the rib of the engaging fastener is aligned with the slide track for inserting into the slide track so that the positioning projection and the positioning recess engage with each other,

wherein said housing is provided with a wireless transmission module therein, and the wireless transmission module is selected from the group comprising: wireless router, wireless IP sharing device, and wireless access point.