Lung model specifications vary depending on whether they are anatomical models designed for education or functional, scientific, or digital models used for research and simulation. 

Here are the specifications based on different types of lung models:

1. Anatomical Lung Models (Educational)

These are 3D models used in schools, clinics, and hospitals to demonstrate human respiratory anatomy. 

• Scale: Frequently life-size or 3/4 life-size.
• Parts Included: Generally 4 to 7 parts, typically featuring the larynx, trachea with bronchial tree, heart (often 2-part), subclavian artery and vein, vena cava, aorta, esophagus, and 2-part lungs with removable lobes.
• Material: Durable PVC (Polyvinyl chloride) or fiber with plastic bases.
• Details: Hand-painted, color-coded segments to distinguish between lobes and bronchial trees.
• Dimensions: Roughly 40–50 cm in height for full-torso models, with smaller, specific lung models measuring around 23 x 10 x 12 cm.
• Weight: Ranging from 388 grams to over 1 kg. 

2. Functional "Lung-in-a-Bottle" Models (DIY/Classroom)

These are used to demonstrate the mechanics of breathing, specifically the role of the diaphragm and pressure changes. 

• Structure: A 2-liter plastic bottle (representing the thoracic cavity) or a bell jar.
• "Lungs": Two 9-inch balloons attached to a Y-shaped connector (straws).
• "Diaphragm": A larger, cut-off balloon stretched across the bottom of the bottle.
• Mechanism: Pulling down on the diaphragm balloon decreases pressure in the bottle, causing the internal balloons (lungs) to inflate.