This device comes with no instructions. The box has the following printed on it: " This Nano SIM cutter designed by our is different with other factory. It has special functions. Both the Micro Sim And Nano SIM cutter are cut by our Nano SIM cutter, because of this cutter has two tool head. So it is very convenience. If buy one this cutter equal buy two other.
All iPhone SIM card will be cut by our newest Cutter".
The cutting of an old SIM card from full size down to Micro and then on to Nano was not achieved. The cutter did not cut cleanly and the Sim card remains too thick to go into my new phone.It will be returned to Amazon in the morning.
I note that the other reviewer, R.D Thomas, who gave it 5 stars has also given 5 stars to everything else that he/she has reviewed.
What a lucky person! 140 reviews and every one is "Very good service and product"
Save your money and DO NOT BUY this item.