3 mm Spanner for Bed Levelling Screws

I needed a couple of spanners to adjust the bed levelling screws on my Prusa Mendel. At first, I was going to download and print one, but then I decided to have a go at my very first real creation (from concept to physical print).

I measured the M3 nuts with my digital callipers (5.4 mm across flats / 2.3 mm thick), and designed a spanner with an open end at one end and a hex ring at the other, using Alibre Design PE(Personal Edition). I increased the gap by 0.5 mm (to allow for plastic shri