Heat blocking window films are designed to reduce the amount of heat transmitted through window glass by reflecting some of the heat back outside but still allow light in to maintain your view. It definitely works wonders for you, keeps privacy, insulates heat, blocks 99% of UV rays, mitigates the glaring sunlight, and helps you to save energy bills. <br><br><b>Tips: </b><br>1, Always put the film on the inside of window and only apply it to smooth glass surfaces.<br>2, Affix tape on a corner of the back side to quickly remove the clear backing.<br>3, Put protective film on window film before squeegee away water and air bubbles, prevent damaging window film.<br>4, Remember to use A LOT of soap/water mixture to soak both the adhesive side and window. <br>5, Please remember to take caution when handling the film as the slightest fold will create a permanent wrinkle.<br>6, A helper is especially necessary when applying film to large windows. Having an extra hand will enable you to steady the film and work through issues if they arise.<br>7,The mirrored exterior depends on the light intensity and angle. The mirror-effect is reversed at night since the interior will be exposed to more light than the exterior. Remember to draw curtain during night.<br><br><b>Don't know how to use it? Don't worry, the static cling film is very easy to apply !</b><br>Step 1. Keep Window or Glass clean<br>Step 2. Wet the Window or Glass with water.<br>Step 3. Remove the Static Film from backing protect sheet, and then the protected side should be post to the window.<br>Step 4. When you install it, Apply to wet glass and smooth with hands. <br>Step 5. Squeegee away water and air bubbles.<br>Step 6. Much easier than Wall Decals, it's no problem for you. <br>Step 7. Enjoy your works!<br><br>GENUINE CUSTOMER SERVICE: Contact us anytime via Amazon for a free refund or replacement, no question asked, no return necessary! Any questions pls let us know and we'll endeavor to respond within 24hrs.