Features: Presented as being of excellent sensitivity and precision, they help you find the best position for DVB-T antenna installation. Designed with a compass for easier and faster adjustment. With ringtone control and attenuation function, easy and user-friendly operation. The feedback numbers indicate the signal strength intuitively. Mini size and light weight, really portable and easy to carry. Operation: 1.Connect the antenna cable on the left to F female and the battery pack cable on the right to F female. Remove any external amplifier* that may be connected to the antenna. 2. Adjust the antenna to the best position by watching the indicator reading. Higher on the scale gives a better signal. If the viewfinder reading is at full scale, adjust the level control knob to reduce the reading to approximately 5 (turn the control clockwise to decrease the reading), continue moving the antenna until the highest possible reading is obtained. 3.Remove the viewfinder and replace any disconnected amplifier. Important note: -If your antenna has an internal amplifier, (for example: 01MM-SQ01), it must be powered by an external power source via a DC insert module. Make sure the electrical insert is placed between the viewfinder and the antenna. Features: Color blue Material: plastic Frequency range: 170-860MHz Input level range: 65-95dBuv Impedance: 75 Insertion loss: 5.0dB Power supply: 9-12V DC Item Size: Approx. 127 * 63 * 35mm / 5 * 2.48 * 1.38in Item Weight: Approx. 90g / 3.2oz Package Size: Approx. 18.6 * 14.1 * 4.3cm / 7.32 * 5.55 * 1.69in Package Weight: Approx. 197g / 6.97oz