Description The operation method is very simple and easy to use.Roll the tip back and forth on the skin to know the sensitivity level by the degree of reaction. Strong Point ♥High quality stainless steel ♥22 metal spikes ♥Non-slip handle ♥Easy to use and storage ♥Comfortable to grip Specification: Material: Stainless Steel Weight: 1.58 Ounces Size: 7.5 Inch Easy to operate It has 22 metal spikes, and create strong sensation, and rolling fan design, adaptable for testing nerve sensitivity by rolling the pointed tip back and forth on the skin.