The division bar weatherstrip fits into the channel on the back of the vent window that the glass rides in. Sold individually - order two for a two-door regular cab truck. Replacement of this weatherstrip eliminates wind noise, drafts, window rattle, and helps to provide smoother operation of the roll-up side windows. This division bar weather strip channel is often replaced at the same time as the windowfelt, and window run channel (both available separately).