The Model ACT-22B 3-Channel Block Coded Key Ring Transmitter is designed for use with Linear’s access control products. The Model ACT-22B 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. Lithium batteries with a five-year service life are included and the transmitter is supplied with a quick-disconnect key ring. A unique 10-second time-out feature prevents the system from being shut down by a single transmitter transmitting continuously.