Sun Tunnel flat roof Flexible tunnel Used for installation in flat roofs, to bring natural light into areas of the house where a flat roof window installation is either not possible or not appropriate. The frame is made of white PVC. Supplied with polycarbonate dome. • Flexible fibreglass tunnel, with reflective inner coating. • Recommended tunnel length for flat roof is between 0.2m and 0.9m. • 0.9m tunnel supplied. • Available in 35cm diameter.