Stonehenge

Hey there, This topic kept me interested as not-registered user for several months now, as I am considering to light up my modulars a little bit, too. I am really impressed of the detailed and precise work! A short question regarding the 3mm tube you are using to cover the cables (you wrote about in the thread-opening-post). Is this a Lego-original brick or third party product? - If so, where did you get that? Kind regards, Stonehenge