A sling or runner is an item of climbing equipment consisting of a tied or sewn loop of webbing. These can be wrapped around sections of rock, hitched to other pieces of equipment, or tied directly to a tensioned line using a Prusik style knot. They may be used as anchors, to extend an anchor to reduce rope drag, in anchor equalization, or to climb a rope.

Slings are an essential piece of gear that you will use every time you head out climbing. A sling is a tied or sewn loop of webbing, that works in conjunction with all your other gear, such as carabiners, quickdraws, cams, nuts and climbing rope. They can be wrapped around sections of rock and used as runners, used as anchors, or even used to ascend a rope. Climbing slings are generally now made with either nylon webbing or Dyneema.