The Firefly 390LMD21K is a compact, single-button keychain remote designed as a compatible replacement for legacy LiftMaster, Chamberlain, and Sears Craftsman garage door openers and gate receivers that use 390 MHz fixed-code technology with 9-position DIP switches. It transmits at 390 MHz and replicates the original fixed-code signal once you match its internal 9 switches to the pattern on your opener’s receiver or on an existing working remote. Ideal for residential garage doors and compatible commercial or community gate applications using the older DIP-switch format, it offers a straightforward, learn-button-free setup that mirrors the original programming method used by classic systems.
This Firefly transmitter is intended for systems previously operated by 390 MHz DIP-switch remotes such as LiftMaster 61LM/62LM/63LM and similar Chamberlain/Craftsman fixed-code models. It is not compatible with Security+, Security+ 2.0, MyQ, or any opener that programs via a learn button. Installation is simple: open the remote, set the 9 DIP switches to match the receiver or original remote code, and test operation with the opener. Because fixed-code systems provide basic security compared to newer rolling-code technologies, use this remote only with existing compatible receivers that are specifically designed for 390 MHz 9-switch DIP programming.