The Round Object Holder is an attachment for the Python Prosthetic hand by Aaron Brown of Axislab 3D which can be found here: https://www.youmagine.com/designs/python-utility-hand-alternative-assistive-device

This design is a modified version of RotoScan's hobby clamp which can be found here: http://www.thingiverse.com/thing:12616

I used the same locking mechanism from the hobby clamp and modified the jaws to resemble V-Blocks that are used in machining

The jaws open ~1 inch and are intended to hold a variety of objects: pencils, drumsticks, nail polish brushes, soldering irons,etc.