Megacode remote garage door opener transmitter by Linear with rolling code technology.   Operates up to three garage door openers  using MegaCode technology .   Each of the three transmitter buttons will send a unique code when pressed.   One button can be used to activate the individual’s garage door opener, a second button can operate an access gate, a third can activate an additional garage door opener or most Linear 318 MHz MegaCode wireless receivers.   Compatible with Linear garage door opener models LD033, LD050 and LS050.  Battery included.   MCT-3 remotes show an FCC ID: EF4 DNT00089 number.