C – Parting bead. There are 2 parting beads positioned on each side from the sash box, operating vertically from top to bottom between the sashes. Each half part of the Ventrolla parting bead consists of a draught-proofing procedure that faces the adjacent sash, forming a snug temperature seal.  The former president from the https://sash-windows41728.blogunteer.com/34743518/a-simple-key-for-sash-window-draught-proofing-unveiled