Specifications: When the door is turned on, it flashes rapidly, warning the rear to avoid the accident occurred. Wireless design, easy to install, just paste on to your car door easily. Waterproof cap and build in high-tech component sensor, long service life. Powered by button battery, easy to replace by yourself. Item Name: Car Door Open Warning Light Power Supply: 2 x Button Batteries (Included) Material: ABS + Metal Light Color: Red, Blue, Colorful LED Quantity: 5Pcs Features: Easy to Install, Magnetic, Wireless, Warning Light Size: 20mm x 9mm/0.79" x 0.35" (Approx.) Notes: Due to the light and screen setting difference, the items color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 2 x Car Door LED Warning Lights