This is a Showa-era steel acupressure tool from Atex. Of course, you can use it with one hand, but you can support the acupressure tool with the black rubber part, adjust the pressure with the white part, and press on stiff areas. The tip is shaped like a finger, so it doesn't hurt. You can also use it by sliding it. Unlike plastic, it's made of sturdy steel, so it applies a focused force.