You get 3 wireless motion sensors, “EACH” requiring 3 - AA battery (Not include). Twist to open, place battery and mount to your desire location using the double-sided tap. Simple as that. I got these under my kitchen cabinet. These work as expected. The light will turn ON when it senses motion and ONLY if the area is dark. It will stay ON as long it as still senses motion and will turn OFF +15 second after it stop sensing motion.  You don’t have to worry about these turning ON during the day and wasting battery.  The light output is moderate but bight enough to service its purpose.