The bohemia x40 cube boasts a large glass window to offer an unparalleled view of the fire and offers a minimal depth into the chimney of just 266mm the x40 cube has a minimalist and contemporary design but its clean burning and high efficiency is far for minimalist boasting an efficiency of 795 when burning wood or 724 when using smokeless fuels with a heat output of 4kw being defra exempt allows the x40 cube to be installed into smokeless zonesthe x40 cube is constructed from 5mm stee