This document discusses products for improving air duct systems, specifically the MEZ-Parallel Coupler. The coupler is an assembling element that allows for quick height regulation or adjustment of threaded rods or grub screws. It provides quick extensions for direct suspensions and seamless elevation adjustment. The coupler is available in steel for M8 or M10 threads in lengths of 35mm and is priced between 38-50 euros per 100 units.