1 1/8" (29 mm) wrench

I modified http://www.thingiverse.com/thing:9704

I have included the shapes.scad file I had to run down on the internet in the SCAD package. The "use" line was not working for me in OpenSCAD.

I adjusted the handle to not be a cube, I needed some clearance in the middle for my intended use on a 3 gallon CO2 bottle.