ADT is a well-known security system brand that’s been in business for 140 years. Still, you may not know what to expect when shopping for one of their systems. Here’s everything you need to know before deciding on an ADT security system.How Does an ADT Security System Work?An ADT system includes motion detectors and sensors that activate if doors or windows are opened. If someone tries to break in, a loud alarm goes off and a signal is sent to one of six ADT monitoring centers across the U.S. Someone from the center then calls your home to see if it’s a false alarm. If a sensor is tripped again, ADT contacts the local authorities.ADT monitoring centers operate 24 hours a day, 365 days a year. This helps ensure there will be a representative available when you need them. You can control your system with the control panel, key chain remote or the ADT app on your phone.Some systems must be hardwired into your electrical system, but ADT also offers a wireless system that doesn’t require drilling or damage to your walls. This is great for renters or people who move often.What Comes With an ADT Security System?ADT works with you to build a package that fits your home’s needs and budget. There are many security packages to choose from, but the basic systems include a control panel, motion sensors, a backup battery for your system, a key chain remote and sensors that detect if doors or windows are opened. Additional options include security cameras, smart plugs, smart locks and a video doorbell, plus smoke and flood detection.You should think about including Two-Way Voice and CellGuard in your security package. Two-Way Voice lets you talk to an ADT monitoring representative through the control panel, even from up to 75 feet away. This comes in handy if you fall, or if there is an intruder and you can’t reach the panel to press the emergency button. CellGuard is a wireless system connects to the monitoring center with a cellular uplink. This can be particularly helpful during a natural disaster when landlines are down or jammed.How Much Is ADT Security per Month?ADT has monthly fees at three price points. The ADT Essentials package currently starts at $36.99 per month and includes an infrared motion detector, a digital keypad, an alarm siren, three door\/window sensors, backup battery, key chain remote, window decals and a yard sign.The second-tier package, ADT Total Protection, starts at $42.99 per month and includes everything in the Essentials package, plus CellGuard. The third-tier package, Premium Protection, starts at $52.99 per month. This includes everything in the first two packages, plus ADT Pulse. This feature connects your security system to your smart home devices and allows you to monitor and control everything from one app.How Much Does It Cost to Have an ADT System Installed?The price depends on the equipment installed. Installation starts at $99 and can go up to $199.Does ADT Have Money-Back Guarantees?Yes, for up to 30 days on DIY installs and up to six months on professionally installed systems.The company also has a theft-protection guarantee. If you’re burglarized while your ADT system is armed, ADT may pay up to $500 toward your homeowners insurance deductible if your situation meets certain conditions.