Standard marker size is 6mm diameter for the reflective portion, and we have the markers for the Mini which are 3mm. The far mode side of the Magic Mat has 10mm reflective circles. Has anyone found a source for markers of that size? Searching for them brings just brings up standard markers since the outside diameter of a standard marker is also 10mm.
Inner diameter 9mm, puter diameter 12mm to buy here. Close enough? 
The inner circle is 6 mm but together it is 10 mm so if the inner is 10 mm the outside should be 14 mm the black circle should be no less than 4 mm to be recognized as marker
Sometimes the stores listens it as inner circle 
and sometimes by outside circle 
If there is not enough black circle around the reflective circle it will be not recognized so how bigger the outside black circle 
how better but not less than 4 mm