Features: Simply install on the air valve. According the recognize color to display the pressure of the tire. Fit on any standard size existing tire valve stem. Visually alerts you when the tire pressure is low to help avoid premature tire wear or blowouts from under-inflated tires. Enhances road handling, increases economy, extends tire life, increases fuel efficiency, safety and control. Easy to control and install. Red and Yellow indication bar: tire pressure at below 2.0 Bar (Less than 75% of the standard), DANGER; Yellow and Green indication bar: tire pressure at 2.3-2.0 Bar (Less than 90% of the standard), WARNING; Green indication bar: tire pressure at normal range (2.4 Bar), SAFE.