Lid module for a cup

A lid module adapted to cover a top opening of a cup body, the lid module comprising:

• a plug device movably and expandably received inside an inner ring to adapt to an inner periphery of a cup body, wherein the plug device includes a plug with a tube and spaced leaves integrally extending out from a bottom of the tube and selectively expandable relative to the tube so that the lid module is able to have a water tight engagement with the inner periphery of the cup body when the plug device is in an expanded status and the lid module is freely movable relative to the cup body when the plug device is in a contracted status
• a lid having an outer ring, the inner ring integrally formed with the outer ring, and
• a hollow central ring integrally formed with the inner ring and having an inner diameter larger than that of an outer diameter of the tube so that the tube is able to extend into the hollow central ring and be securely received therein and a securing mechanism integrally formed with the inner ring.