This is used as a leash to connect your harness to a bolt, protection, ice screw, anchor or something solid. It is a popular alternative to the daisy chain used in rock or ice climbing. The standard daisy chain as a flaw that, when used without proper instruction, can lead to disaster. Though daisy chains do a great job be sure to understand how they work. Check http://www.bdel.com/videos/daisy.html for more information.Due to the material it is made of it is not recommended for activities where you end up above your anchor, such as canyoneering. (The founder of ATS, Darren Jeffrey, demonstrated how easy they can fail in those situations.)