A cardiac Allison lung retractor (large) is used during thoracic and cardiac surgeries to gently retract lung tissue, providing a clear surgical field for procedures like lung resection, lobectomy, or pneumonectomy. The "large" size is one of several available options, selected to accommodate the specific surgical scenario and patient's anatomy. Its flat, spatula-shaped blade and hollow handle are designed to minimize pressure on the lung, ensuring maximal ventilation and reduced tissue trauma during these delicate procedures.