When evaluating ENT headlights, the most critical factor is Illumination Intensity (Lux); for deep cavity examinations, a range of 30,000 to 100,000 Lux is recommended. The Color Temperature should ideally be between 4,000K and 5,500K to provide a natural daylight effect, which is essential for accurate tissue differentiation. Additionally, check the Spot Size Adjustability, ensuring the beam can be narrowed for ear canal inspections or widened for throat exams, typically ranging from 10mm to 80mm at a 420mm working distance.