The Lift Masters worked as advertised - well sort of - but they work fine. Glad to have found them. I bought two sets and have two garage doors.When pairing each receiver and 2 Transmitters, it helped to use the test mode in the directions first before going thru walls or floors of a house. If you don't do this, even short distances were not reliable pairing. (I use pairing as if pairing your hands free cell phone to your car or ear piece- same idea here.)After pairing the first set and installing them (I have 2 garage doors to monitor), the Lift Master worked fine.Pairing the second set monitor had difficulties thru just one wall and only 25 feet from the garage doors.Pairing the second set monitor required going into the garage to pair the second receiver. Apparently the pairing signal is much more sensitive to distance and quality of the signal. This is a good thing to help protect against hackers. Once I programmed this set in the garage and moved the receiver to the second floor, about 45 feet away on a diagonal, the unit continued to work first time.I found that using a hand held garage door opener, the old kind that hangs on your car visor, a great help in expediting the verification and operation of doors and Lift Master indication. I could stand in my hallway downstairs and look up to the master bedroom to see the monitor lights. I could then open or close either garage door and hear it and watch the lights on the Lift Master. (Sure helped since my wife was not home when they were installed.)After two weeks they are still working fine. By the way I have aluminum garage doors and mounting the transmitter at the top of the doors does 2 things: it help reaching upper floors and gives an indication if the garage door is only 1/4 open, which I do sometimes because of pets. This is Lift Master recommended location.My only complaint, which is a preference rather than a problem, is the black AC power adapter cord from the Receiver to the outlet it is plugged into. Since most walls are not black, this cord shows up like a arm cast. Solution if done carefully, I painted the cord part, not the plug or the module, with the same paint as our wood trim and mounted each receiver by a door frame so the cable could be attached and made less visible. It would seem the manufacturer could easily have made this a white cable, since the majority of people do not have black walls to make the cord look less obvious. Do not try to hide the cord by running it thru walls. This cable is not suitable for concealed wiring.Glad to have made the purchase.