Thermostat

FIG. 1 is a top, right front perspective view of a thermostat showing our new design; FIG. 2 is a bottom, left back 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 broken lines in the drawings depict portions of the thermostat that form no part of the claimed design.