Advantage functions: 1. No tar and other carcinogenic substance. 2. Harmless to other and the environment. 3. No danger of second-hand smoking. 4. Smoke in a public place. 5. Enable smokers to abstain from smoking non-painfully. 6. Give up smoking in 3 month if you want. 7. Save the smoking cost 80% each year. 8. No ignition and no fire hazard.