Moistureproof and Fireproof 1. Light weight 2. Temperature insulation 3. Fireproof: gypsum core is noncombustible,absorb heat to postpone rise of temperature. 4. Sound insulation: special cavum structure, improves sound absorption performance to a large degree. These are both decorative and functional. I have 507 pieces (13 tiles per sealed box) of 2'x2' drop in ceiling tiles for sale that cover over 2000 sq ft of ceiling.