Edelweiss O-Flex is a single 9.8 mm diameter rope designed for indoor climbing. It is in fact a classic rope without waterproofing treatments but it is also an extremely resistant rope. Thanks to the O-Flex treatment, this rope will be very soft over time. It is also equipped with a special sock technology called 3D Cover which makes it very smooth to the touch to limit friction. Instructions for Use. Edelweiss O-Flex 9.8 mm climbing rope