Application: This car engine start switch can be used for additional electronic equipment inside and outside the car; start your vehicle's engine instantly with the push of a button. Excellent Replacement: For ignition activation, a direct replacement for the old one. LED Light: This car switch has a built-in bright white LED light for easy nighttime visibility. Waterproof: Made of high-quality metal material, waterproof, stable, and Easy to Install: Easy installation, universal fit for most vehicles; Installation diameter: 19mm/0.7in