Borrowed some crowfoot spanners, but they had hooked openings so they couldn't slide onto the bolt from the side. Made some with straight openings to overcome the problem.
15mm, 16mm and 17mm as I'm not sure exactly what size the nut is due to its location with variants to fit either 1/4 or 3/8 inch drivers. Each one is .2mm oversize to to accommodate some shrinkage.
This is the very first thing I ever made with Tinkercad. Super quick and dirty, so feel free to improve.
Edit it online https://www.tinkercad.com/things/87KAcwFx7AI
For regular FDM probably use ABS or ABS PC @ 75 - 90 % infill.
Markforged go for Onyx or CF reinforced.
DLP machines try ABS Tough type material.
Recommend HP MJF for strength.