These decals are used for : Protect birds from hitting against the glass because they can not see the glass or glass. Made of PVC, doing a good of keeping your furry flying friends from into the picture windows. It is a self-adhesive backing that fit for smooth surface glass doors and windows. Features -Color:Assorted Color -Material:PVC -Size: 15.00X12.20X0.10cm/5.89X4.79X0.04in -Note:Random Style -Butterfly shapes, offers a vivid design for your home window decor. -Easy to use, just clean the window and then stick the anti-collision window cling. -If you want to rearrange it, simply peel it off and move it around. -The specially designed reflective material in each window cling reflects ultraviolet sunlight as glowing warning sign for birds. -They appear as frosted or to humans. Package list: 1 x set of 20pcs stickers