When selecting perforated acoustic panels, the Noise Reduction Coefficient (NRC) is the most critical metric; look for values between 0.70 and 0.95 for optimal sound absorption. You must also specify the perforation rate (open area percentage), as a higher percentage generally improves low-frequency absorption but may impact structural integrity. Ensure the base material is High-Density Fiberboard (HDF) or Fire-proof MDF for durability, and verify that the thickness (typically 12mm, 15mm, or 18mm) aligns with your project's acoustic requirements.