This is a set of 10 slim card-type RFID skimming prevention cards. I used a few, and the rest were kept new and unused. One card has a line on the back (see image 3). - Quantity: 10 cards - Function: RFID skimming prevention - Color: Silver Although unused, these items have been stored at home. Please examine the images carefully, and refrain from purchasing if you are looking for a perfect item.