Chamberlain/Liftmaster 971LM Security Plus 1 Button-Sears/Craftsman Compatible 390 MHz Liftmaster 971lm transmitter is compatible with orange or red learn codes Operating range: 100ft- authentic Liftmaster product- OEM Operates on a 3 volt lithium battery Frequency of operation: Rotating Transmitter: 1 - button, 390 MHz frequency, code rotating technology (security+)