This rubber window channel is felt flocked and sold by the foot. It is used exclusively for convertible models - 1931-1932 Cabriolet & Landau Phaeton with chrome window frames on the door glass. This channel has 9/16" opening. Not for use on vehicles with no metal framework on glass - See also 70-1168 for 5/16" wide channel. Measure from the top of the window opening down to the lower window stop, add up total inches and divide by 12 to get total number of feet. Used on most GM convertibles in this era.