Linear et-2 keychain garage door opener Features and Specifications One button keychain size remote with 256 possible codes Standard Linear digital format, part number SNT00055, also compatible with part number SNT00016. 8 dip switches, 303.875 Mhz frequency Compatible with 8 dip switches openers with 303.875 Mhz frequency For use on alarm system, lighting control, video surveillance and certain garage door openers