The Tibloc is light and compact ascending tool that should always be in your pack if you’re carrying rope. It’s perfect for self-rescue in a crevasse and ascending a rappel that didn’t quite make it to the dance floor. Rather than carrying around a full-size ascender, just hook a carabiner through the hole and the angled directional teeth go to work. The body is made of corrosion resistant stainless steel to improve longevity while the self-clearing capabilities of the angled teeth increase bite when conditions are muddy, icy, or wet. The Tibloc is faster than a prusik, lighter than an ascender, and small enough that there’s no reason not to have it with you just in case.
Update 2018: The Tibloc got a bit of a makeover. Aside from the orange color, the new version has has an automatic system that presses the carabiner against the rope to start the braking action on the rope. This is significant with use of smaller diameter ski mountaineering cord, making it easier to use, quicker to "bite" on the rope, and more efficient.