Since its inception in 2005, the Unicender has been the most flexible tool for tree climbing. With the ability to be used in both Doubled Rope Technique (DdRT) and Single Rope Technique (SRT), the Unicender fits the way you like to climb like no other tool. The Unicender utilizes unique friction plates that allow it to advance easily with minimal friction, and virtually no “Sit Back,” giving you the most efficiency per stride. Additionally, the Unicender attaches conveniently mid-line. For rope sizes 11 to 13mm, or 7/16” to 1/2”.