Combination of large and small covers for water bag

摘要

A combination of large and small covers for a water bag is provided on a water bag, composing a base, a cover of large diameter coupled to the base, and a cover of small diameter mounted onto the cover of large diameter. The base has a vertical wall, which is vertically provided with an extension rim around the periphery of the bottom, the vertical wall of the base is provided with exterior threads. In the center of the cover of large diameter is provided with a hole with interior threads for coupling with the exterior threads of the base, whereas the cover of small diameter is provided with exterior threads at its periphery and a switch piece on the top. Thereby both of the covers of small diameter and large diameter can be easily rotated to open and close for various utilities.