I remember back when home alarm systems required that an installer run wires to every door and window that needed to be protected. This required some carpentry work and wall and other surface repairs to cover the damage done during installs. New wireless systems allow any home to have a security system installed with no cables needing to be routed through walls and floors. We got ADT in Tulsa who came out and installed our home security system. It was easy and clean with no muss or fuss to have it installed. The sensors are powered by lithium batteries that last for many years before needing to be replaced. When a battery does start to get low on power, it notifies the control panel of the alarm system to let you know it will soon need to be replaced. The batteries can be purchased in pretty much any department store, and you can install them yourself. It only takes a minute to pop in a new battery. Most of the detectors and sensors use a standard CR123 lithium battery. I really do mean they can power a wireless alarm sensor for years. The window and door sensors are small and unobtrusive. A criminal casing your house to burglarize it will notice the sensors. They have a trained eye to spot these things. Other folks won’t even notice. As an aside, this is why just buying a yard sign telling people you have an alarm system is not good enough. You need to have sensors installed on your windows. Criminals will actually use binoculars to get a closeup view to look to see if you really do have an alarm system or not. They are not fooled by someone just putting up a yard sign. We do have the yard sign, but we also have the real thing as we got our security system from ADT in Tulsa.