Linear ACT-22 Keychain 318mhz megacode 2 button garage door opener

The Linear 1-Channel or 3-Channel Key Ring Transmitter is designed for use with Linear's access control products. The Model ACT-21A is a single-channel device supplied with a quick-disconnect key ring. The Model ACT-22A is a three-channel device. Pressing the transmitter's left or right front button sends channel one or two. Pressing both buttons sends channel three. 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.