I don't carry a phone book anymore, I have a cell phone. With our dependence on devices that we can lose and break sometimes it does mean that we lose all of our contact information. The SIM card backup tool is a very inexpensive way to backup or copy up to 500 phone book entries from your phones SIM card. This device is even capable of copying to a different type of card. Great way to make sure you don't lose your contacts ever again!