Alarm Detection Systems, Inc. (ADS) is one of the leading providers of electronic security in the nation. We are the largest privately-held electronic security company in Illinois. ADS is a family owned and operated business with a long history of satisfying customer needs and providing outstanding customer service. We have been in the industry for over 54 years with over 300 employees in Illinois, Wisconsin, Indiana, and Colorado. We sell, service, install and monitor commercial and residential fire and burglar alarms. Join our team and become a valued member of an elite organization filled with dedicated people. For more information about our company, please visit adsalarm.com.