Sunlight reaches the cabin as visible light, ultraviolet and infrared energy, and infrared is the invisible part most responsible for the warmth you feel through a window. Kepler's nano-ceramic films are built to work across that spectrum at the glass, which is why they can address solar heat without needing to be dark. On a Tesla, with its large glazed areas, that tends to show up as a cabin that is more comfortable to sit in and trim that spends less time in direct sun. Your installer can compare the IR and IR+ ranges, shade for shade, against how you actually use the car.