1byone High Gain Low Noise HDTV Antenna Amplifier Signal Booster for TV HDTV Antenna with USB Power Supply, Boost Any Non-amplified TV Antenna up to 15 Miles Range Gain 20dB Color White This amplifier/booster can enhance signals weakened by obstructions between you and your local broadcast towers. The number of channels you can receive is determined by what's being broadcast in your area. Channel reception is dependent upon distance from broadcast towers, terrain, surroundings, and weather. Check out what channels are available in your area first and how many you are able to receive. If your TV picture is not crystal clear, or you cannot receive the weak signals from far away towers, use this amplifier to boost the weakened signals. We do NOT recommend using this amplifier/booster if your house is very close to the broadcast tower and the signal is already very strong. The amplifier may cause self-oscillations and result in fewer signals received. We offer a 90-day money back guarantee if you find this amplifier does not help to strengthen received signals.