Dakota Alert Solar Powered Wireless Infrared Break Beam System Bundle Break beam sensors are powered by lithium ion batteries that are recharged through the solar panels during the day Solar powered wireless infrared break beam system that is simple to install and requires no wiring May be mounted high enough to avoid dogs or other animals; still detect any intruder walking through beam Infrared sensing terminals can be mounted up to 300 feet apart and will send a signal back to the DCR-2500 receiver up to half mile away anytime someone passes between the sensors Operating Range: -30F to 120F