Businesses in the burglar alarm category supply, install, repair and maintain systems designed to detect unauthorised entry into homes and commercial premises. Systems commonly include a control panel, door and window contacts, motion detectors, internal or external sirens and keypads or fobs for setting and disarming the alarm. Installers may assess a property's layout and recommend the positioning and type of equipment, including wired, wireless or hybrid systems. Customers may also find alarms with smartphone controls, notifications, panic buttons, or sensors that detect glass breaking. Some providers arrange ongoing maintenance, fault repairs and battery replacement, while others offer remote monitoring services that receive alarm signals and follow agreed procedures when an alert is triggered. Work can include upgrading older equipment, adjusting or extending an existing system, and explaining how to operate it.