This guide outlines best practices for ensuring the security of card readers in compliance with the latest PCI DSS physical security standards. It details the recommended checks to perform when receiving and installing a new Cantaloupe card reader or all-in-one payment device. Users are instructed to verify the integrity of tamper-evident seals, check the display for tampering indications, confirm the firmware version, and inspect the touchscreen for any physical overlays. Additionally, it emphasizes the importance of regularly checking the device for any signs of tampering, such as holes or suspicious objects around the card slot and MSR slot. The guide also advises users to verify the serial number against records. If tampering is suspected, it provides contact information for Cantaloupe customer service for further assistance. The document serves as a comprehensive resource for maintaining the security of payment devices.