Check the listing for details. Linear ACT-34B ACP00872 Mini Block Coded 318MHz Remote Transmitter MegaCode Ring. Condition: New. Listed at 25.50 USD. Linear ACT-34B ACP00872 Mini Block Coded 318MHz Remote Transmitter MegaCode Ring The Model ACT-34B 4-Channel Block Coded Key Ring Transmitter is designed for use with Linear’s access control products. The Model ACT-34B is a four-channel device supplied with a quick-disconnect key ring. Also included are lithium batteries with a five-year service life. A unique 10-second time-out feature prevents the system from being shut down by a single transmitter transmitting continuously. The transmitter is MegaCode format, which means each transmitter is factory preprogrammed with one of over 1,000,000 codes, virtually eliminating the possibility of code duplication. Because the receiver ”learns” each specific code, no unauthorized person can gain access to the system by reprogramming a transmitter. Block coded transmitters are factory programmed to a sequential series of transmitter ID codes. When used with a Linear access controller, transmitters can be locally or remotely programmed into memory by entering the first and last codes of the block into the system. Facility codes can be selected to further customize the system. Features Compatible with all Linear access receivers and controllersSupplied with quick-disconnect key ringPower: Two 2016 batteriesCodes: Factory block coded in MegaCode formatRF frequency: 318 MHzDimensions: 1.25″ W x 2.25″ H x .48″ D