Super easy to install - the chimney parts just clip together (no glue or sealants required except for the roof flashing) and the bottom of the chimney just inserts into the stove with a wrap of sticky-back fireproof webbing. Ever heard of Meccano kits? You get the picture. Because twin wall pipe has clip-on locking bands a chimney made only of twin wall (without vitreous pipe at all) is very strong structurally. Hence only one bracket is required. If this bracket is not aesthetically pleasing it can be swapped for a roof/rafter support that can be hidden in the roof area. 5" twin wall has a outer diameter of 192mm and 6" has a diameter of 217mm.
Because it is insulated the flue pipe can be as close as 5cm to wood and is completely safe (7cm if the flue is boxed in). It typically gets no hotter than a radiator. For more info on combustible materials and hearths etc. see WHAT YOU NEED TO KNOW below.