Many credit and debit cards and enhanced drivers licenses have a Radio Frequency IDentification Chip. Protect your personal information. RFID blocking RFID card holder are designed to safe guard you from electronic pickpocketing. Elastic finger loop for easy holding. Adhesive backing securely attaches to the back of cell phones. Holds one card.Item Size: 3 3/4 W x 2 1/2 HImprint Area: 3 1/4 W x 1/2 H