Oil oak, a tree species of eucalyptus in Myrtaceae, is tough, dense, moth-resistant and corrosion-resistant. Rich in a variety of natural essential oils beneficial to human health, such as eucalyptol, pinene, rest anisaldehyde, piperidone, fennel, etc., it can strongly release phentermine and negative ions (air vitamins). Its special fiber structure can strongly absorb and release water, and shrink through wet expansion. Large-scale indoor use can achieve the effects of sterilization, anti-inflammation, air purification, immunity improvement, blood pressure reduction, tranquilization, brain strengthening and anti-aging. Large-scale indoor use can create a healthy and beneficial environment.