Solar energy reaches your Tesla as visible light, ultraviolet light and infrared, and it is the infrared portion you feel most directly as heat. Kepler's IR and IR+ ranges are nano-ceramic films engineered to work on that energy at the glass, screening ultraviolet light and managing infrared so less of it ends up warming the cabin. Because that performance comes from the film's construction rather than its darkness, visible light transmission is a separate matter: a lighter shade is not automatically a poorer heat performer, and a dark film is not automatically a strong one. The practical result for a Tesla is a cabin that heats up less in the sun, climate control that has less work to do, and interior surfaces that get some protection from long-term UV damage. Glare is reduced too, which many owners notice first on bright afternoons. When you are comparing options, look at the published figures for the exact film and shade you are considering, and ask the dealer handling your enquiry to compare IR and IR+ for your model.