This chamber set includes all of the components required to form a 450mm diameter inspection chamber - one base section, two 235mm sectional risers and a 560mm square polypropylene cover and frame (450mm clear opening).The overall depth of the chamber from the invert level to the top of the manhole cover is 800mm. If you need to make small adjustments to the height then the sectional risers may be cut to size using a standard fine-toothed saw. Alternatively if you need to increase the height of the chamber you can add more D916 risers up to a height of 1200mm with the standard cover and frame (or up to 3m if you use a CLKS499 access restrictor).The main channel of the base is left open and the side inlets are blanked off with integral blanking plugs - simply remove the blanking plug by pushing it out from within the base to open and use the side inlets.The cover has a 35Kn load rating making it suitable for use in domestic driveways. It has a dual locking facility and the frame itself can be adjusted by 15 degrees to suit out of level surfaces.For more information on this product, please watch the brief video below.