suitable for KS3+. A first hand view of how the lungs work! This simple, yet effective apparatus consists of two sacs which represent the lungs, a rubber membrane which serves as the diaphragm and a clear plastic enclosure which models the chest cavity. By making the diaphragm relax and contract the students can see how the lungs are emptied and filled with air. Size: 6.5ﾔ (D) x 5ﾔ (H).