New England Ropes has an interesting web page entitled "Micro Rappel" where they show a kit for emergency, personal rappelling using a 5mm or 3mm rope (yes, 3mm). They also depict a descender I've never seen before, possibly unique to their system. They list "emergency rappelling line" as one of the applications for their tech cord.<br>http://www.neropes.com/maxim_climbing/micro_rappel.htm<br><br>They manufacture what they call "tech cord" with a polyester cover. Tensile strength is 5,000 lbs and 3,200 lbs for 5mm and 3mm respectively.<br><br>The thought of a rappel on 3mm rope scares the daylights out of me -- I don't care what it's made out of.<br><br>Another article I found related to micro rappelling:<br>http://www.sbccom.army.mil/products/cie/MicroRappelSystem.htm<br><br><br><br>