This device did absolutly nothing to help my reception.  I tried it in a dozen locations in the house with several phones.  I have VERIZON and usually have good service, but not in the house.  The device blinks red when the antenna is too close to the booster.  In several cases, I had the antenna as far away from the booster as the booster plug and the antenna line would allow, still blinking red.  When I did get a green light, there was no change in my one or two bar signal on any phone.  Useless machine.