Solar energy reaches the cabin as visible light, ultraviolet and infrared, and infrared is the invisible part that carries much of the heat you feel through glass. Kepler's nano-ceramic films use ceramic particles within the layer stack to manage that energy before it reaches the interior, which is why performance is not simply a matter of how dark the film looks. The result is a cabin that heats up less in the sun, less glare through the windshield and side glass, and ultraviolet filtering that helps protect trim and upholstery from fading. Each film and shade has its own published figures, so compare like for like when you are deciding, and ask your installer to confirm the numbers for the option you choose.