This 5/16" diameter vinyl bulb seal has a 1/8" wide base. It is designed to fit in the channel at the top and bottom of many jalousie (louvered) windows to cushion the top and bottom panes as they close against the aluminum frame.
Please carefully measure the width of the channel on your window to verify whether this is the correct seal for your window. Price is for one 10-foot length.
This seal fits the Hehr 1600 series jalousie windows with 4' tall panes used on many vintage Airstreams and dozens of other makes. For instance, an owner of 1962 Avalon trailer reports this fits his trailer.