A CDMA Rubber Duck Antenna with a TNC connector is a flexible, compact antenna designed for CDMA (Code Division Multiple Access) networks. It features a TNC (Threaded Neill-Concelman) connector, which is a threaded, weatherproof connector often used in applications requiring a secure connection. These antennas are commonly used in various CDMA devices, including 2G/3G devices, IoT devices, and some older systems. They are known for their durability and ability to provide reliable signal reception and transmission, especially in environments where a more rugged connection is needed.