This device can protect your vehicle from potential thieves. The bright flashing LED lights simulate the lights used in expensive car alarm systems. Causes thieves to pass by your car in search of an easier target. No installation required- wireless. Includes two alarm warning decals. Measurements are 3 inches x 1 inches x .75 inches (at the tallest point). Requires 2 AAA not included.This device can protect your vehicle from potential thieves. The bright flashing LED lights simulate the lights used in expensive car alarm systems. Causes thieves to pass by your car in search of an easier target. No installation required- wireless. Includes two alarm warning decals. Measurements are 3 inches x 1 inches x .75 inches (at the tallest point). Requires 2 AAA not included.