Privacy Screen Uses A Microlouver Technology That Darkens The Screen View From The Sides (+/- 30 Degrees From Center) - Designed To Fit Laptops With 13.5" Displays And 3:2 Aspect Ratio; Does Not Interfere When Closing The Lid - Flip-Over Mounting Feature Enables Quickly Flip-Over The Privacy Filter To Share Contents Without Uninstalling The Filter - This Laptop Privacy Screen Blocks Up To 51% Of Blue Light - Use The Included Adhesive Strips Or Flip-Over Tabs To Install The Screen Protector