Adjustable spanner wrenches with interchangeable tips will greatly simplify your life. Different slots will require flat tips with different thicknesses, for example. And the ability to re-orient the tips (facing inwards or facing outwards) allows you to get into tight places where a single-purpose spanner will not fit. Avoid buying the cheap spanner wrenches that are black anodized - they are wobbly and are of poor quality. I would strongly recommend the spanner wrench with interchangeable tips from Fargo Enterprises/Micro Tools. I have used a number of spanners from other sources, and none compare with the build quality and utilitarian value of the spanner from Micro Tools.