Pack of 100 cardboard and Mylar coin holders measuring 1.5" x 1.5" square with a 21mm opening, suitable for nickels. Guardhouse paper holders are super clean, dust free, and easy to staple with mini staples (10-5m). They are made of high quality cardboard with a white surface, making them easy to write on, and premium Mylar to offer great long term protection for your coins. This type of holder is the most common holder used for coin storage and display. To use them simply fold it over with the coin in the window and staple the holder around the outside.