This is a torsion block system designed for Hollies hand Version 4 (http://www.thingiverse.com/thing:696343). It was inspired by James Holmes Siedle's talon-torsioner. There are two torsion cylinders. One is for turning via a screwdriver. The other in theory should be hand turnable. So the good news is that it works well. It allowed for hand tensioning of the tendons. The increments could be a little smaller but they did a pretty good job. Just have to get the rest of the hand working well.