With a swipe, this device encrypts your credit card number, enabling online purchases without fear from viruses or malware (a fraudster's spy software) that may reside secretly on your computer. Eliminating the need for manually typing in your credit card number, the swiper plugs into your computer's USB port. The included software works with your browser such that when you go to a website and are ready to purchase an item or service, a swipe of your card through the device encrypts your credit card data before it reaches your computer. The software then inserts the encrypted number into the credit card field on the website you are visiting. The software never stores your credit card number on your computer. Can also be used with most major debit cards. Works with Windows 7, Vista, and XP. 3" L x 2" W x 1 1/2" H. (6 oz.)