The 500mm Starter Pipe with door has a built in condensate ring at the bottom of the pipe that allows direct connection on to a continental style spigot. There is also a built in sweeping door to allow sweeping of the chimney. The pipe leaves a clean look to the connection off the top of the stove. High temp silicone or cement must be used under the condense ring to make sure a gas tight seal is made with the stove spigot.