The cold and hot hammer utilizes the principle of thermal expansion and contraction. When the skin is at 5 degrees Celsius, it reduces the rate of metabolism and slows down sensitivity. The hot hammer at 5 degrees Celsius temperature enables nutrients to be quickly absorbed, reducing wrinkles and crow's feet. The cold hammer can effectively contract pores and repair damaged skin.

Cold hammer: contraction of pores, soothing of the skin; hot hammer: acceleration of nutrient absorption, promotion of metabolism.