Features：
1. Realistic anatomical structure, include tongue, oral pharynx, trachea,
epiglottis, glottis etc.
2. Intubation via oral/nasal cavity
3. Head lift to open airway
4. Blow to inflate lungs or stomach to verify intubation position
① Inserting to respiratory tract, air feeding, lungs will be inflated
② Inserting to esophagus, air feeding, stomach will be inflated