 It has a built-in battery-powered LED backlight that illuminates the old films and slides and then puts them right inside the free Kodak app. It's not expensive. It's about $35. So if you want to save some money, let me tell you, it's cheaper to make the film and slide kit all by yourself. There are just a ton of how-to tutorials over on YouTube. Just search for DIY Film Scanner. Once again, that's DIY Film Scanner.