4 Pieces Per Pack -- Light dimming filter are made of environmental film, the size is 8.2x11.8inches/21x29cm.You can cut it into various shapes and sizes.50% ~ 80% brightness covers -- Light blocking film will dim 50% ~ 80% of any electronic lights. It helps you sleep quickly and deeply without light distractions.Blocking annoying Light -- on electronics and appliances, such as alarm clock, radio, car screen, air conditioner, refrigerator, monitor etc. in the home or office. Readable Electronic Number -- This light dimming sheet can reduce the light while displaying the LED numbers and indicators clearly. Easy to Use -- You can stick anywhere as you want. It will not leave a sticky residue when you remove them.