The mounting bracket is used to attach 100mm plastic duct to existing duct mounting iron-work. i.e. It allows additional ducting to be fitted to existing mounting brackets or suspension rods. This kit suits 5/8" (16mm) rods, but can be used with 1/2" (13mm) rods and nuts, where desired. Includes 100mm duct mounting bracket (Part No: TC1279-14).