Plastic Back Box (Plenum Boxes) Top Entry - 450mm sq with 250mm dia spigot

The Plastic Back Box, also known as a plenum box, is a top-entry box that connects a circular duct to a square grille or louvre. Its durable plastic construction fits standard duct sizes and makes installation straightforward. Connects a circular duct to a square grille or louvre Top-entry spigot for the round duct Durable plastic construction, easy to install Smooths airflow behind the grille 15 combinations of square face (150 to 550mm) and spigot (100 to 315mm) Suitable for Joining round ductwork to square grilles and louvres Homes and commercial buildings, behind ceiling or wall terminals InstallationFits behind the grille or louvre, with the circular duct connecting to the spigot on the top of the box. Match the square face to the grille size and the spigot to the duct diameter. Specifications Type Plenum box (plastic back box) Entry Top entry (spigot on top) Square face sizes 150 to 550mm Spigot sizes 100 to 315mm diameter Function Connects circular duct to square grille or louvre Material Plastic Warranty 1 Year Manufacturer