You don't need to spend thousands of dollars in order to hook up an easy-to-install basic security alert system. The Household Alert Combination Set is an expandable system that provides both visual and audible indicators when its wireless sensors detect a breach. The garage door sensor alerts you if you leave the garage door open, and the motion sensor can detect movement either inside or outside your house, with a range of up to 40 feet. Best of all, the Household Alert Combination Set is easy to set up, with the sensor alerting the receiver wirelessly. The motion sensor requires a 9-volt alkaline battery, sold separately. Mount the motion sensor indoors or outdoors, anywhere you fear security may be breached. The garage door sensor mounts near the bottom of your garage door and sends a wireless signal to the receiver in your house when the garage is opened. With its range of 300 feet, you'll be able to place the receiver in any convenient location in your home. The included receiver will control up to four different sensors. Sold separately, you can add a Household Door/Window Alert Sensor for security, or a Household Water Alert Sensor for water leaks. Additional motion sensors are also available. If you don't need both the motion sensor and the garage door sensor, you can instead purchase a kit with the receiver and either the motion sensor or the garage door sensor. When multiple sensors are installed, only the corresponding zone LED will flash, so there will be no confusion. In addition, you'll know which zone is being triggered by the number of beeps emitted in succession. If you're planning to be working in an area that normally triggers your motion sensor, or if you're planning to leave your garage door open while you work in your garden or on your car, the audible alert can be muted easily.