These lightboxes feature dimmable LEDs that provide an even spread of light from edge-to-edge. They are ultra slim at .31" thick and light-weight. The lightboxes include a built-in ruler grid and are ideal for tracing, calligraphy, stenciling, embossing, quilting, embroidery, sewing and more.The LED bulb will last approximately 50K light hours. They are powered by an AC adapter and produce very low heat. Cable measures 71"