Flat Oval Spiral Duct Look at the beneath video clip to see the installation of oval duct and fittings. Recognize that the reducer being used is undersized on its collar allowing the oval duct to slide in excess of the collar. They may be using Unistrut with threaded rods as https://roundconduit35677.livebloggs.com/43063654/round-conduit-no-further-a-mystery