The ornamental design for a water-saving device for toilet tank, as shown and described.
Description:
FIG. 1 is a perspectiv view of a water-saving device for toilet tank embodying the design of the present invention;
FIG. 2 is a side elevational view thereof;
FIG. 3 is a top plan view thereof;
FIG. 4 is a bottom plan view thereof; and,
FIG. 5 is a perspective view shown on a reduced scale of the water-saving device for toilet tank in use. The broken line showing of environment is for illustrative purposes only and forms no part of the claimed design.
