What I have seen could be the insulated flex is shown as duct, and also the foil uninsulated flex is mentioned as an air connector (if mentioned in any way). In either scenario, the product must be Ul 181 authorised as a way to be applied. A chemical reaction where https://emiliocfggh.mybuzzblog.com/15065798/new-step-by-step-map-for-aluminium-plat