The Screw Fix Adapter to Chimney Liner connects single wall stove pipe to a Flexible Flue Liner of the same internal diameter. This 316 grade steel adaptor has a threaded metal connector allowing it to screw onto the flexible chimney liner. The 60mm tail single wall end connects to your vitreous stove pipe So easy to install, no fire cement, no self tapping screws to secure it, just an easy thread that screws directly onto the liner to provide a secure and tight fit.