Impact Resistant Design --- Each window sticker is designed with reflective material that reflects UV light and acts as a warning light for birds. To humans, they look like frosted or etched glass. Safe and Durable --- These window stickers are made from self-adhesive vinyl. You can remove these window stickers at any time and they won't leave any residue on the glass. Wide range of applications --- You can stick them on window panes, porch doors or ledges of window, they can be used as a mirror with reflection of sunlight and are a great decoration on your windows or glass doors, bringing much fun to your life. Effective measures --- --- When attaching kangaroo windows to glass, make sure they are spaced no more than 15cm apart to keep birds from hitting the window as much as possible.