One key aspect of hardware design is choosing an appropriate form factor for your product. In today's world, form factor not only defines your product's size and shape but also includes its aesthetic appeal. While size and shape are important, another aspect that is prominent when dealing with RFID card readers (including NFC and BLE mobile credential readers) is the reader's location within the end device and the size of the RF antenna. This article focuses on some key considerations relating to form factor and other physical specifications that play a role in integrating card readers.