This is a simple, lightweight device intended for crevasse rescue. It is made from the same 5mm polyester cord a the Micro-Prussik. One end has a 30cm loop, used to tie a prussik hitch on the rope, the other end has a 40cm loop, to put your foot in. Length can be 120cm-150cm.  I recommend you play around with a piece of string and the system you want to use this with to find the length, I probably can't advise you on it. 
 
End-to-end strenth is 8kn. A three-wrap prussik on all of the 6mm ropes that people have tried has always held body weight. 
 
Be sure to check out my blog post about different friction hitch fibers here.