FIG. 1 is a perspective view of a transmitter showing our new design; FIG. 2 is a front view thereof; FIG. 3 is a rear view thereof; FIG. 4 is a plan view thereof; FIG. 5 is a bottom view thereof; FIG. 6 is a left side view thereof; FIG. 7 is a right side view thereof; and, FIG. 8 is a perspective view thereof in a state wherein an antenna is rotated.