This spanner works great with A, B and C type fittings, it is still ok to use with D but not really intended for it.

I recommend to print it with 8 perimeters and 5 solid top and bottom layers. This way it has enough strenght and doesn't break. You should also print the front part solid, anything else will be too weak. I have a picture without top and bottom Layers attached, infill type doesn't really matter i used hexagons in the picture since it looks cool, for others i used gyroid.

I tried breaking it intentionally but have failed so far. I used PETG since i don't want it to warp if left in a vehicle and it has some give to it which helps.