Working principle: Made up of permanent magnets, the bio-composite heat-chip Moxibustion consists of tourmaline, nano-functional ceramic powder and a special heat sensitive materials Adopt nano biotechnology, with dual effects of thermoelectricity & piezoelectricity, form a resonant magnetic field resonates with the human body Applicable range: This self-heating pad is designed for your waist, applicable to bone hyperplasia, shoulder pain, joint pain and other symptoms of hyperthermia therapy Product performance: Effectively improve blood circulation, promote metabolism, and clear the meridians, enhance immunity Velcro closure: With two elastic Velcro belts, easy to take on/ off, convenient to adjust the tightness to fit all sizes Type: Self-Heating Belt Feature: Self-Heating Function: Stimulate blood circulation, Promote metabolism, Enhance immunity Material: Nylon, Spandex, Tourmaline Color: Black Suitable Part: Waist Belt Length: 93cm Belt Width: 15.3cm Net Weight: 177g / 6.24oz Note: If the body part appears redness, fever, hyperthermia, it is a normal phenomenon With time, heat intense will become weak and the heating time will get longer Do not use the product in sensitive parts such as eyes