The first Volas EMS Foot Massage Pad with Pulse Technology photo is a black square pad with two outlined foot shapes.
Sit on a stable chair, put both feet on those outlines, then use the top control as the in-box steps describe. The page does not say to stand on it or to use it while walking. The image file name mentions a balance board; the picture is still a foot pad.
Open the Volas foot pad page.