Sensors systems vary significantly with add-on options similar to purchasing a brand new vehicle. For most of us the fundamental alarm package is a good example. The fundamental system provides window and door alarm contacts on all openings, a number of infra-red-colored motion sensor inside, an audible horn or siren, along with a user interface having a digital dialer system and keyboard. Past the fundamental security alarm you can include hard-wired smoke and warmth sensors, glass break sensors, ultra-sonic and infra-red-colored motion sensors, temperature sensors, shock sensors, user interface tamper sensors, battery back-up, and mobile phone signal confirming technology. I have seen trendy houses with sensors monitoring the temperature in wine cellars and caviar fridges.