This Micro to Standard SIM card adapter is designed to have 0.5 mm clearance around the micro sim. This allows for the contraction associated with cooling plastic while still allowing for a loose fit. Designed with SolidWorks.Print the included STL file, making sure that is flat on the print surface. After cooling, remove carefully, and gently push the micro sim card into the hole, making sure both the adapter and the card are in the same orientation. Use the resulting assembly as you would a normal SIM card.