This is a circular digital timer. You can adjust the minutes and hours by how quickly you turn it, and it has a magnet, so you can set and stop it in seconds. Just press the round part to turn it on, and it enters energy-saving mode a few seconds after setting, then the display turns off. To stop it, just press the round part again, and a long press resets it. The outer ring has a non-slip design, making it easier to use than push-button types. There's a switch on the back for two volume levels and silent mode. It can be set from 0 to 99:55 minutes. It's 7.78cm x 7.78cm x 3cm and weighs 71g without batteries. Please use it during gym workouts, yoga, and more. It comes with 3 AAA batteries, so you can use it right away.