Control unit for easy and accurate detection of in-phase polarity of all home theater, audio and video devices. Connecting all devices to an in-phase high-performance power socket (such as Oehlbach Powersockets or Powerstation) prevents ground loops and maintains excellent acoustic sound and imaging and interference-free visual display. The tester is easy to use and reliable, it works with solid technology. Its cabinet consists of a robust, high-quality aluminum body case. The phase device is powered by a standard 9 V battery (included).