In the App Stores, it ain't Free Speech Bumper Sticker + 3 Additional Stickers - High opacity film that’s impossible to see through Durable vinyl, perfect for indoor use 95µ thickness Fast and easy bubble-free application - Follow these tips when applying stickers: Apply the sticker to a clean, dust-free, oil-free, and moisture-free surface. After application, press the sticker down with a clean cloth to maximize the sticker’s ability to stick to the surface and avoid air bubbles. Make sure that the sticker is applied correctly the first time. With every reapplication, the sticker’s ability to stick will decrease. Apply the sticker to a flat surface only. If applied on items that bend, are round, or in a cylinder form, we can’t guarantee its ability to hold.