C – Parting bead. There's two parting beads positioned on either side from the sash box, working vertically from best to base involving the sashes. Every fifty percent part of the Ventrolla parting bead has a draught-proofing system that faces the adjacent sash, forming a snug weather seal.  Gordon Ramsay's 'viral' lazy scrambled eggs https://pendant-ceiling-lights38383.eedblog.com/35960689/sash-window-draught-proofing-an-overview