The Unicender by Rock Exotica is an all-in-one ascender/descender that works in both single and doubled rope techniques (SRT and DdRT). This unique “mechanical split-tail” designed replaces the friction element (tied hitch) of a DdRT tree climbing system. Invented in 2005 by arborist Morgan Thompson and now produced by world-renowned machining phenomenon Rock Thompson of Rock Exotica, the T6 alloy Unicender also functions cleanly on single line for abseiling and is not limited to use by professionals only— recreational or beginning climbers will find it a rewarding investment for occasional to regular use as well. The Unicender is considered inherently less complicated than separate ascender and descender devices because there is no dangerous changeover at the top of the climb, affording seamless transitions from ground to crown and ground again.