Most all home security systems are for internal use-inside the home. The voice alert system works outdoors. It can be used for businesses as well as homes.\nThe Wireless Alert System has a base unit and receivers\/transmitters. The passive infrared motion detection technology in each receiver\/transmitter sends a signal to the base unit. When motion is detected, a prerecorded message announces what is going on. It has an effective range of up to1000 feet in open space and up to 300 feet through walls. Users record their own message-for example, “someone is entering the driveway” or “someone is in the pool area”. The unit sets up in minutes and everything you need for installation is included\nYou can check out all of our Wireless Alarm Systems to see if one of them will work for you\nFeedback on these posts is welcomed. Have you ever used the Voice Alert System? Please share your experience. We want to hear your thoughts.\nThe Home Security Superstore is one of the oldest and largest independent distributors of high quality home security, surveillance, spy, self-defense, survival and safety products. We carry a wide range of self-defense products including tasers, stun guns, pepper sprays and other nonlethal weapons that can save your life in the event of an attack.