G – Ventrolla Perimeter Sealing Process (VPSS). The Ventrolla Perimeter Sealing Process (VPSS) comprises many draught-proofing features that operate collectively to seal the whole perimeter of the sash window. These involve the sealing system set up above the top sash, either within the sash itself or in a few parting bead facing the https://steveh172qyg9.mybuzzblog.com/profile