The Keystone Heddolf CRC390-1KB is a single-button handheld garage door opener remote designed as a compatible replacement for Chamberlain, LiftMaster, and Sears Craftsman operators that use Security+ rolling code at 390 MHz. It transmits a secure rolling code signal to open or close a door or gate with one press, making it a practical upgrade or replacement for lost or worn transmitters. Typical OEM equivalents include LiftMaster/Chamberlain Security+ 390 MHz remotes such as 971LM and 973LM, and compatible Craftsman models. Ideal for residential garages and light commercial operators, it’s engineered to deliver reliable operation with Security+ encryption to help prevent code grabbing.
This transmitter programs directly to the opener’s receiver via the Learn button—simply press and release the Learn button on the head unit (red/orange on Security+ 390 MHz models, commonly found on units manufactured roughly 1997–2005), then press the remote’s button to sync. It operates on the 390 MHz Security+ frequency and is not compatible with newer Security+ 2.0 systems that use a yellow Learn button (tri-band), Security+ 315 MHz systems with a purple Learn button, or older Billion Code units with a green Learn button. For best results, program at the opener and verify proper operation of safety reversing sensors after setup. This Security+ 390 MHz compatible transmitter serves as a dependable replacement part for Chamberlain and LiftMaster users seeking a straightforward, learn-button programming remote.