Linear Multi-code 3089 300 MHz 1-Channel Visor Transmitter (10pcs) Model 308911 is a poratble transmitter designed for automatic door & gate operator applications. Single-channel device, pressing the push button will send a signal to the receiver Multi-Code format with one 10-position coding switch providing 1,024 possible codes. The transmitter will only activate receivers set with the same code Model 308911 is compatible with 300 MHz Multi-Code receivers and machines