PERFECT SIZE: The size of the CR80 cleaning card is 3.375 inches X 2.125 inches, and the thickness is 0.03 inches. This is the standard thickness for credit cards, so don't worry about it not fitting into your card printer/reader. It works with most card and card printers. FAST & EFFECTIVE CLEANING CARD: The liquid on the card reader cleaner quickly cleans your machine of residue and dirt. You don't need to wait too long after cleaning, it will dry quickly, and the card reader can be used normally immediately after drying. REDUCE CARD READER FAILURES: Individually sealed packages do not allow CR80 cleanig cards to dry out and are more suitable for regular cleaning. Weekly cleaning prolongs the life of the heads and prevents the build-up of dirt that can cause data read errors. HOW TO USE: Step 1. Take out the credit card reader cleaner. . Place the cleaning card into the card reader like a credit card. Step 3. Turn the card over and repeat until clean. & RESIDUE-FREE: The card reader cleaning cards are fully functional and perfect for cleaning any type of magnetic stripe reader, card printer, card reader, credit card machine, vending machine and optical card reader. Colour:White Material:Plastic Package Contents: 50 * credit card reader Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.