This is a pre-made sapele handle for the Woodchuck Pen Pro and Uni-Tool. Installation instructions are included with the Pen Pro instructions. The handle is 8" long and 1.2-1.6" in diameter. You will want to glue the copper ferrel to the handle when you assemble the tool.
These are handmade and the exact diameter can vary from handle to handle. If you have a specific dimension, please inquire before ordering.