The dual pattern sheath on the Sterling Marathon Pro 10. 1mm Rope makes the line's center point stick out like a sore thumb and saves you tons of time on climbs and descents. Quick identification of the center point ensures both ends are equal when you're making the fifth rappel in a row, and lets you know if you have enough rope to lower your partner off the 15 bolt sport route he just sent. You'll love the easy rope management provided by the dual pattern the next time you're re stacking line at a hanging belay. The Sterling Marathon Pro is also extremely easy to clip thanks to its 10. 1mm diameter, and its light weight of 63gm won't weight down your pack when you head out on another alpine approach.