Inner circumference: 17cm
The metal part is made of copper, the internal elastic cord is made of silicone.
It can help individuals achieve mental focus and enhance cognitive vitality. With a frequency similar to brainwaves, it has a calming and soothing effect, alleviating irritability and restlessness, treating insomnia, and dispelling troublesome nightmares. It aids in the development of intelligence and potential, improves memory, and assists in overcoming detrimental habits such as alcoholism, smoking, and indulgence.