Using this card holder is a breeze. Just put your cards inside and use the key clasp to attach it to your backpack, keychain, or other items. If you want to display your ID, place it in the clear plastic window. To clean it, you can wipe it with a damp towel, with or without soap, or use a disinfecting wipe. After cleaning, let it air dry or dry it with a towel. Since it's made of coated cotton, it's water - resistant, but avoid submerging it in water for a long time. Also, be gentle with the key clasp to prevent it from breaking.