I tested it on the back of my hand only once. It's practically unused*. I'm selling it because I don't have many opportunities to use it. (Please purchase if you understand that this is a used item.) &ROSY SPRING Supplement WHOMEE × Shinobu Igari EMS, Heat, and Vibration Facial Device × 1 Size (approx.): H176 x W35 x D25.5mm Weight (approx.): 49g *Uses 2 AAA batteries (not included in the supplement)