The 9.5mm Fusion Ion Dynamic Rope by Sterling is a small diameter rope that is made with a unique construction giving it amazing strength and a supple feel. The Ion is super smooth, with easy handling and awesome clipping abilities due to its light weight of 60g per meter, but can still handle up to 5 UIAA falls The Ion also offers the missing link between the 9.2mm and 9.8mm sized ropes with its 9.5mm - a great millimeter size for working hard sport routes, or alpine climbing. The Ion is part of the Fusion series, which is a hybrid of the best elements of the Sterling Marathon and Evolution ropes. The Fusion series ropes are the lightest, skinniest single ropes Sterling has made.IMPORTANT: Due to these ropes small diameters, it is recommended they only be used for onsights, redpoints, and NOT for top-roping or working of routes. It is critical that proper belay devices be used and extreme caution should be taken.