There are three holes for one 10X3 Magnet or two 6X3 Magnets.
Use the ones that you prefer.
Those are the magnets that iused :
Example:
You shall not share, sub-license, sell, rent, host, transfer, or distribute in any way the digital or 3D printed versions of this object, nor any other derivative work of this object in its digital or physical format (including - but not limited to - remixes of this object, and hosting on other digital platforms). The objects may not be used without permission in any way whatsoever in which you charge money, or collect fees.