look at the antenna ( usually next to rear mirror, or high up by the windshield, it should indicate a model number, with that go to internet to search, you can find it out an alarm system using same type of transmiter to match it. * e/ @( l! }, K1 c( yDepends on how many function, one way or 2 ways etc. , R! |8 u m# I- cDo you remember the style and look of the one you lost ?