21W square ceiling lamp: Health and Environmental Protection warm you and me 1. PMMA(acrylic) shade,higher light transmittance,Light scattering, to create a comfortable light environment. 2. High tri-phosphor, longer lifespan, high efficiency energy-saving, return home, food the true color. 3. No flicker, no noise, protect eyesight 4. Cold-rolled base sheet, powder coating processing and rust-proof, no rusting for 8-10 years under indoor use.