These moldings are for the "American Style" rubber which have molding grooves.
Type "A" refers to the electroplated metal molding. They are American made and brightly electroplated. They come complete with clips.
Type "B" molding is plastic with a metallic finish. The "B" molding comes as a roll with two clips: enough for one front window OR one rear window OR two quarter windows. Thus, you will need three sets to do all four windows on a 71-77 sedan.
Please review the restoration tip below concerning the "American Style" and "Cal Look" seals.