Limo tint is also known as a 5 percent tint because it only lets in 5 percent of the available light. When describing tinted windows, a lower percentage number corresponds to a darker tint.
According to HowStuffWorks, a limo tint blocks 65 percent of the sun's heat and 99.9 percent of its ultraviolet radiation. The limo tint is only legally allowed on the back and rear vehicle windows in most states. Limo tints reduce visibility to the outside of the vehicle, especially at night. They also limit the ability of the driver to interact with pedestrians and other drivers through eye contact, facial expressions and hand motions.