Rex, The Electronic Watchdog Who Can See Thru Walls

What do you think, is this fake dog for real?

Rex II, the electronic watchdog alarm, never needs sleep, a walk, food or water, yet is always on duty guarding and protecting. In addition to the choice of a ferocious dog(s), Rex II also offers a siren or greeting announcer. Rex II is versatile and provides an excellent way to deter burglars, without the annoying problems of owning a real dog. With his electronic radar eyes, Rex II can "see" through thick doors, walls and glass. Once his cord is plugged into any standard 110 VAC electrical outlet (or install six C batteries), he'll stay on duty around the clock.

$60 bucks seems cheap for radar.

Related: Startup Launches Home Intrusion Detection and Tracking System (Xandem)

Apparently, it uses ultrasonic frequency @ 2.45 GHz. I bet some walls or obstacles kill the range of that thing fast. uses ultrasonic frequency...

Why do you think it uses sound waves, not radio waves?