At each change of smartphone, now arises the question of the compatibility of the SIM card. With this cutter, no problem. We can adapt mini cards to micro and nano and micro to nano. What is best is that three plastic adapters are provided. We can therefore turn back easily. In addition, I can easily please the guys who have not particularly want to run to their operator to change the map. It works like a hole punch. When the card is removed, a small nail file blow to refine the edges and it's perfect. There are no manual but engravings on the handle indicate how to position each card template before cutting. The unit is all metal, simple solid and cheap.