Solar energy reaching your Tesla arrives as visible light, ultraviolet and infrared, and infrared is the invisible part many owners notice most as heat. Kepler's nano-ceramic films are engineered to work across that spectrum, which is why a lighter Kepler shade can still be a serious heat film. Because visible light transmission and solar heat performance are separate measures, compare the published data for the exact film and shade rather than judging by how dark the glass looks. Reduced solar heat also means less glare and less UV reaching the interior, which helps protect trim and screens over time.