Good day I am interested in the following monitor holder: https://www.digitec.ch/de/s1/product/ergotron-lx-dual-stacking-arm-tisch-40-monitor-halterung-21282933?ip=ergotron+l However, I would like to extend this with an arm. I saw on the Ergotron homepage that there is an extension arm: https://www.ergotron.com/de-de/produkte/produktdetails/98-130#/?color=Schwarz&farbe=Wei%C3%9F I wanted to know if I can order this (in black) from you and how much the extension would cost.