The division bar weatherstrip fits into the channel on the back of the vent window that the glass rides in. Sold in pairs since one weatherstrip is needed for each front door on the 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).