perfect little emergency ascender!
i really love this! it's super lightweight and works great. i got two so there's one for my foot and one for my harness. for the foot tibloc, i made a loop of 8mm cord to stand in. i took the advice of one reviewer and got two petzl attache locking biners to use with them. the attache fits through perfectly and the teeth in the tibloc bite down nice and solid. i've never had to use them in an emergency, but i've strung a rope up in a tree several times to practice using them and getting hooked into them mid rappel and have been very pleased with the ease of use and simplicity of design. like others have said, be sure to put a small cord through each one so that you don't accidentally drop it.