Credit card readers, or magnetic stripe readers (MSR), are used to read the magnetic stripe on plastic cards, gift cards, credit cards, driver's licenses, security badges, etc. They're most often used for credit cards. Mag stripes have 1, 2, or 3 tracks of data. Gift cards, id cards and other specialty cards often use track 3. Track 1 & 2 are typically reserved for credit card use. Most credit card readers allow you to enable or disable tracks. MagTek and ID Tech have been sold and supported for many years by POS World.