The MMCX connector is a miniature RF connector commonly used in telecommunications and electronics. It's designed for applications requiring high-frequency transmission, typically in the range of 6 GHz. "MMCX" stands for "Micro Miniature Coaxial" and it features a snap-on coupling mechanism for easy connection and disconnection. These connectors are compact and lightweight, making them suitable for applications where space is limited. They're often found in devices like GPS receivers, Wi-Fi antennas, and cellular devices.