We have had quite a few requests to make a Spindle Square for the world market that works with Metric collets and reads in native units. We have built a new spindle square just for this that offers all of the same adjustments but fits this world market demand.
The spindle square is adjustable with 8mm holes for 75 - 150mm. It can be used to tram on multiple vise sizes, and machines such as your mill, drill press, sine bar and lathe. You can use any indicator with a 8mm stem so you can install a brand or resolution of your preference. The hardware will never rust and shouldn't damage your indicator unless you over-torque the thumbscrew.