3M control tack provides safe, long-lasting hold. Options for in or outside your car or truck. Weather-resistant and waterproof. Our window decals come in 3 sizes - 5"x5", 8"x8" or 12"x12". Inside- vs. outside-glass • Inside-glass decals have printing on the cling side, and go inside your car. • Outside-glass decals cling on the back and are applied to the outside of your car. (If you have tinted windows, this is the only option you can use.) • Don’t use car window decals on your windshield or front windows. • Avoid placing decals anywhere that blocks your vision when looking behind you. • Be sure to check if there are any rules and regulations in your area. *Artwork size varies by design. You may want to do some trimming to get rid of empty space.