I bought three of these clocks at the same time for each of my bedrooms. They all functioned the same way with no defects. Some people have complained that the time will not set. Per the instructions, you must hold the "Up" button on the back for 2 seconds until it beeps, then release. It will then begin trying to receive a signal to set the time. If after about 15 mins if it hasn't updated, repeat the process and try again. It may be helpful to place the clock in an elevated place where it can receive more easily. The backscreen does not automatically light up, so if your room is dark, you wont be able to read it without manually stepping over to the clock and pressing the button on top to light it. It stays lit for a short period of time and then goes dim. This is a battery powered device, so lighting the clock does create a small energy drain. That's why it doesn't stay lit; you would have to change the battery every few weeks if it stayed lit all the time. It takes 2 AAA to power it. There are small holes in the back so it can be mounted. Your time zone has to be selected manually when you first power it on. (I think the default setting was Pacific). Its a durable clock. The least useful feature about the clock is it has a built in thermometer which gives the ambient temp of the room, so that's something most people will not find useful as opposed to the weather conditions outside, but its just not connected to the daily weather forecasts, so don't expect it to give you anything more than the temperature of your room. Its kind of useless for my needs, but whatever, its an attractive clock and I wont have to worry about setting it very much, since its atomic, I know the time is accurate. That's the main reason that I got it. There's also a little kick stand on the back if you want to stand it up on a desk or table. There's an alarm feature that I didn't go into. I don't use mine as an alarm clock. Can't comment on that. I recommend this purchase and I'm pleased with it.