Petzl Rumba 8mm is the new twin and half rope standard for technical rock and ice climbing. The Duratec Dry treatment is in fact the latest in terms of treatments for the waterproofing of the rope and therefore makes it resistant to water, humidity and dust, as well as abrasion. The EverFlex heat treatment of the strands stabilizes them with the result that the rope always remains flexible and manageable over time. The Middle Mark marks the middle of the string, which of course is very useful when maneuvering. Instructions. Petzl Rumba 8 mm climbing half rope