It is a blue dial with 24 plastic pieces like petals; you press them upward, then turn the whole thing to show the time you want, and then lower the petals, e.g. from 1 to 6 if you want it to turn on from 1 in the afternoon until 6 in the evening, then it turns off by itself and you plug it into the outlet. On the right there is a switch: up means it does not follow the setting, like it is bypassed, and down means it follows our setting. It also has a little clock on it. There is also a video on YouTube. I have had them for 3 days, very good, they turn off and on when they should. Only one of the two started making a sound like a timer, not loud; if you are in the next room you cannot hear it. It is useful to connect, for example, an electric mosquito killer, and when you are away and it gets dark it starts by itself and is more effective because if you are there you turn on many lights or, for example, a night light. For economy, it turns off when it should and does not waste electricity when you are watching and it has already dawned, or when to stop a portable device that you are monitoring the battery of, or, for example, when to start a coffee maker if the button is pressed... After a while it makes noise when it turns off; if you sleep lightly it will bother you, if not, get it.
