BDF NA20 Window Film Daytime Privacy and Sun Control Natural Black 20 (Dark)DARK, BLACK FINISH that provides excellent daytime privacy, making it hard for unwanted eyes to see through. EXCELLENT HEAT REJECTION. Helps reduce cooling costs, especially during the summer through the effective blocking of harmful solar rays. NOT RECOMMENDED for DUAL PANE WINDOWS. STRONG ADHESIVES to last many years. For easier installation, remember to use A LOT of soap water mixture to soak both the adhesive side and window. HIGH QUALITY