Pre-saturated cards instantly clean magnetic heads on point-of-sale card readers, access control card readers and more. Just swipe to clean; non-abrasive and easy-to-use. 25 individually packaged, pre-moistened cards per box. Convenient 3 3/8" x 2 1/8" Cleaning Cards. Application: Access Control/ID Cards; Credit Card Readers; Applicable Material: Plastic; Chemical Compound: Isopropyl Alcohol; Dirt Types: Dust.