Derma roller contains Titanium needles, can be applied on any part of your skin. Its application principle is by way of stimulating the dermis layer of collagen and fibroblast proliferation.
It is a flame-retardant electronic temperature control heating cap. The inner embedded plastic film is waterproof and anti-electricity, and it's detachable and convenient to be washed. Two level of temperature controlling, you can adjust to your favorite temperature.