Inovonics S3453A EN1224 4 Button Inovonics TXThe EN1224 pendant is a four button, four condition transmitter. The transmitter must be used with an EchoStream universal serial receiver, security only serial receiver, or with the network coordinator. In addition, the application controller (e. g. control panel) must be designed to accept the multiple conditions Frequency 900 MHz Dimensions 3. 0" x 1. 6' x 1. 0" Battery BAT608 Battery Life 3 5 years