Metal Sputter film works by reflecting solar energy before it passes through the glass. Basically, the darker and shinier the film, the more solar energy it reflects. Sputter film provides optimal heat reflection and durability. The metallic technology within the film's manufacturing process makes it clearer and more durable than other types, ensuring long-lasting use. It blocks 99% of UV radiation and over 90% of infrared radiation depending on the shade (*infrared radiation only contributes to heat reduction). Enhanced protection is guaranteed for 7 years, meaning it won't peel, warp, or crack within the warranty period.