The Expedition Ascender incorporates the most comfortable handgrip ever seen on an ascender. Ergonomic design cushions the hand and provides a great gripping surface. Easy to open with one hand. Designed to be used by a single person to climb ropes from 5/16″ (8 mm) to 5/8″ (16 mm). When used as an ascender for the weight of a single person it will not damage the rope. Made in the U.S.A.