This product is a set of two security doorstop alarms by U.S. Patrol, featuring a loud 90dB alarm sound. The silver alarms are 1.75" in height and have a model number of JB5536. Manufactured in 2014 in China, these doorstop alarms are brand new. Designed to deter intruders and provide a sense of security, these alarms are a practical addition to any home surveillance system.