Thermostat Device

FIG. 1 is a top, front, right-side perspective view of a thermostat device;

FIG. 2 is a bottom, back, left-side perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a back view thereof;

FIG. 5 is a left-side view thereof;

FIG. 6 is a right-side view thereof;

FIG. 7 is a top view thereof; and,

FIG. 8 is a bottom view thereof.

The dashed broken lines depict portions of the thermostat device that form no part of the claimed design. The dot-dashed broken lines represent a boundary of a display area of the claimed thermostat device and form no part of the claimed design.