This product worked great in my dads's apartment. My parents live in a brick build where cell service is bad no matter what the carrier. Outside the building the signal is strong for most carriers but inside terrible. I usually get 1 bar to no bars with numerous drop calls on ATT.  Now I get three bars and no drop calls. I use the suction cups on the window to hold the device and it was enough to improve the signal. Setup was not that difficult and the instructions are clear. Now mind you one must have a good signal outside first as the device just boost the signal inside. If you have no signal outside this product won't help you inside. Im glad I purchased it.