45 degree drill guide

This is a tool for drilling 1/8" pilot holes at 45-degree angles. I designed it for vertical use, but I guess it would work on any other surface too.
There are two visual aids to help you line up the guide tube with where you want your hole to be. If you make a mark 1cm below your hole center, that will be visible through the diamond-shape cutout in the middle of the part. A mark 1 inch below your hole center will line up with the bottom of the part. And a straight vertical line will go through the top and bottom cutouts.
Designed in Autodesk Fusion 360 (.f3d archive is included)