Saily is an international eSIM service that provides mobile data plans for travelers, allowing users to access the internet in over 200 countries without needing a physical SIM card or paying expensive roaming fees. Developed by Nord Security, the company behind NordVPN, Saily works through a mobile app where users choose a destination, purchase a data plan, and install a digital SIM directly on their device. The connection activates automatically when arriving at the destination, offering prepaid, data-only plans with flexible sizes and durations. Unlike traditional carriers, it does not include phone numbers, calls, or SMS, focusing purely on internet access, and often includes added features like security tools and easy plan management for frequent travelers.