Operation is simple. Just hold it in your hand and switch it on. It effectively targets the upper arms through the palms of your hands. This is an EMS product for the upper arms, invented by a software engineer from Estonia, a Nordic IT powerhouse. EMS stands for "Electrical Muscle Stimulation," a device that stimulates muscles by passing an electrical current through them, causing them to contract. Five different approaches: V, O, N, M, and IE. The timer is set for 15 minutes each, but even if you let go, you can change to a different mode and aim for a total of 15 minutes of use per day. The VONMIE ARM CONTROLLER is equipped with a monitor that displays intensity and time. Body size: 167.3 x 135.1 x 38.6mm Power supply: USB charging