Guardhouse 2x2 staple cardboard holders, 3 - Hole Penny/Cent. Packed in bundle of 500. Guardhouse paper holders are the most widely used coin holders in the industry lined with mylar that does not tear or scratch and is also the most moisture resistant film available. Just insert the coins, fold over and staple. Staple type coin flips are inexpensive, easy to use and archival quality, which makes them an excellent choice for long term storage of your collection.