1.It is composed of a light transmission plate with a double respiratory system diagram of a pigeon, a light emitting element group, a mechanical grating and a control circuit board. The light emitting element group is lit and extinguished by a control circuit board. It can dynamically demonstrate the expansion and contraction of the double respiratory system and airbag of pigeon, which overcomes the defect that the existing model or demonstrator can not be dynamically demonstrated. 
2.Size: 70*15*44 cm