• Dual LED lights flash when an incoming call is detected on your cell phone. • Perfect for cars, motorcycles, and noisy office environments. • Also great for preventing noisy interruptions during meetings and sensitive phone calls. Allows you to turn your cell phone to "silent" mode and still not miss a call. • Includes CR2030 battery and velcro tape for quick attachment and detachment. • Works from up to 5 feet away from your cell phone. • Compatible with most cell phones (operating in the frequency range of 800 to 1900 MHz). May not work with PCS phone systems.